What did 243 heads come on

Jun 5, 2020 · The 243 heads have larger intake and exhaust ports than the stock heads, allowing for an improved airflow that increases torque and horsepower. With this increased airflow comes a greater capacity to burn fuel efficiently, giving you better performance overall. Additionally, these upgraded 243 heads are designed with a higher-lift camshaft so ...

NEW GM LS 243 HEAD - 4.8L, 5.3L & 6.0L. $349.99. Generation III V8 cathedral intake port cylinder head. Casting 12564243. For truck, van, SUV and perfomance applications. Used on LS6, L33, L20, LH6, LY5, LMG, LC9,LS4, LH8, LS2, LFA, LZ1 engines. Add to Wishlist. Skip to the end of the images gallery. Skip to the beginning of the images gallery.The 799 and 243 casting Cathedral-port cylinder heads can be CNC ported to flow close to the aftermarket heads. With a bigger cam you can mill the heads for up to 10.8 compression which runs on pump gas. ... If you're gonna do a L33 swap into anything you may may as well leave the 799/243 heads that come one it. Yes I have seen L33s with a ...Porting the 243 heads is an effective way to improve airflow into and out of the engine, as it involves modifying intake and exhaust ports for greater efficiency. With this modification, air flows more easily into the combustion chamber which results in increased power output. In addition, installing these ported 243 heads will also enhance ...Equipped with the 317 heads, the turbo 6.2L produced 807 hp at 6,800 rpm and 747 lb-ft of torque at 4,900 rpm. The boost pressure peaked at 7.6 psi, before dropping to 6.9 psi at 7,000 rpm. The ...The valves on LS3 heads are designed to be larger than those on stock LS heads to improve airflow, leading to increased power output. Standard valve sizes for LS3 heads include 2.165 inches (intake) and 1.590 inches (exhaust). However, it's not uncommon for LS3 heads to feature even larger valves. For example, some aftermarket LS3 heads may ...The 187 casting data came from a Fast355 PM, and some came from Vizard's book Build & Modify Chevrolet SB Cylinder Heads. They confirm other tests on L98 heads. The 081 head (305 v8) was added because 081 (and 416) are often mentioned as being decent factory heads.Sep 1, 2017 · The LS6 also received better (243 castings) heads, a slightly more aggressive cam, and a much improved intake manifold. The LS6 cam is the most aggressive cam GM put out for cathedral port headed ...

Stock 243 heads are good for a budget build, daily driver, or small cam motor, but to get the most out of your setup get a nice set of aftermarket heads. Now my "other" LS1 runs 243 heads (bought complete for $400) and a GM Hotcam (218/227 .525/.525 112 LSA) and made almost 400RWHP and TQ.We would like to show you a description here but the site won't allow us.Did the 5.3 come with 243 heads? Of course, today's 5.3 and 4.8 both have 243 heads that are factory-designed. 243 heads were included in the LS6 engine produced between 2001 and 2006. You can determine the 243 heads on the 5.3 by examining the three-digit stamping next to the valve cover.243 heads Besides the heads... What do I need to put the 243 heads on my 2001 2500HD with the 6.0l? and... Is it worth it? Will I still keep my low end torque? I'm really just interested in better fuel economy. Thanks Reply With Quote. 03-15-2010 10:22 PM #2. PitchBlackC3.Upgrading LM7 Cylinder Heads. The stock heads can be CNC ported for more airflow and milled up to .030 in. for more compression. Flow numbers can be as high as 325 cfm at .600 lift. Lightweight hollow stem LS3 valves can be cut to 2.000 in. to fit the seats. Between the light valves and better springs, the engines will pull cleanly to 7000 …

Feb 25, 2011 · Exhaust flow at .600" - 180 (241) / 183 (243) The 243 heads have a D-shape exhaust port that improves flow and came with higher lift valves springs. Both heads came with 2.00" intake valves and 1.55" exhaust valves. To my understanding, this is all the difference. Last edited by R6cowboy; 02-26-2011 at 01:52 PM.7477 posts · Joined 2005. #29 · Nov 2, 2013. Stock 243 heads are good for about 20 hp on a 2004 LS1 and can often be found for about $400 or so. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow.On our Mast heads, the LS3 head offered both more intake and exhaust flow than the cathedral-port heads, resulting in an intake-to-exhaust flow percentage (372/261 cfm) of 69.89 (meaning the ...Jan 3, 2009 · Just a rule of thumb, Most your 70's 454's will come with either the 781's or 049's unless it's a early rectangle port motor. Once you get to 1980 you start seeing way more of the 454's with peanut port heads. I won't list actual years, this is just a rule of thumb when I am looking to get a 454 core motor. 1968 Chevelle Sb.07-16-2007, 08:03 PM. # 2. Y2Kvert4me. Race Director. Member Since: Oct 2002. Location: Gone. Posts: 16,477. Likes: 0. Received 18 Likes on 15 Posts. CI 6-7-8-9-10 Veteran. St. …

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The seat insert itself is 2.02", so going bigger than that would be pointless without swapping out the seats. To use a 2.04" valve on a stock seat, you would have to cut the seat small at 2.02" so it is still on the iron seat, which I don't think is any better than just using a 2.02" valve. If the seat is cut bigger, some of the valve contact ...The 243 Heads are cast iron cylinder heads that have been CNC-machined to create larger intake and exhaust ports. The combustion chambers have also been machined to be smaller, which increases the compression ratio. While the 243 heads are not the newest or best option out there, they offer a great value for the price.Grr. 1503 posts · Joined 2008. #23 · Jun 24, 2012 (Edited) Got mine running today! Heads are milled .125 total, from stock from what I can tell. I cc'd again and got 46.75cc. ended up with a 7.300 pushrod lifter preload is about .035-.040, and notched the pistons .120, which is as far as I was comfortable with.LSX3rdGen. The 241 head is a stock ls1 head it was on the f bodys and also on the ls1 vettes. They were produced between 2000 and 2003. they are the same as the 853, the 853 was made from 1997 to 2000. ls6 heads are 243's.The 243's have bigger valves which do better on 4.0" and larger bores. On the smaller 3.898/3.78" bores of the LS1/6 & all 5.3/4.8's the 706 are very decent. On a 4.00" bore of an LQ4 though it is splitting hairs. On the same cam, on the same engine, the heads are going to perform within +/- 5hp/5tq of each other, it is almost meaningless.

The 243 head came on the more powerful LS6 engine from 2001 to 2006, and was used in C5 Corvettes. Later engines like the truck-spec LQ9 and LQ4 used the …Identical heads would be the 799s. They don't have the cult following of the 243s, so they're often found cheaper but they're the same head, just cast at a different plant. The only difference in the "regular" 243 from the LS6 243 is that the LS6 version had lightweight valves and special springs.But, the combustion chambers are bigger than the 5.3 heads. You need to mill the 243 heads about .020" to keep the compression ratio the same. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow.This also means that they are usually cheap to collect or replace. 706 heads tend to be more popular than 243 heads with those who run naturally aspirated engines. While they don't have the same size combustion chamber they also don't have the tendency to lower the compression ratio and reduce horsepower. When looking to replace your heads ...34 posts · Joined 2015. #1 · May 21, 2018. My 04 gto has full bolt ons headers, cai, slp 2.5 exhaust and already been dyno tuned. 346hp. 365tq I'm going to bolt on ported 243 heads and upgrade the valve train for the 228r cam. What would be my new hp-tq numbers?? 228-230 duration at 50 588-588 lift. 112lsa m6 trans.799 LS Engine Cylinder Heads are some of the most recent cylinder heads on the automotive parts market. The cylinder cast architecture is with a semi-permanent mold method. The 799 cylinder heads are in the similitude to the 2004 LS2 cylinder heads due to the triangle casting marks similarity. However, unlike the 243 heads, they do not require ...With the above heads, the peak flow was reduced to around 260 cfm from 298 cfm at .600" lift. This is important as the head and Manifold work together, giving a more realistic indication of the potential horsepower to be gained. The head may flow 320 cfm, but with a stock intake bolted up, you can loose 50-60 cfm of peak flow.Find Parts and Accessories 243 heads KEYWORD and get Free Shipping on Orders Over $109 at Summit Racing! Use your Summit Racing SpeedCard today, and get up to 10% back - Get Details! ... Cylinder Heads, Remanufactured, Assembled, Aluminum, Natural, Buick, Cadillac, Chevy, GMC, Hummer, Isuzu, Pontiac, Saab, Workhorse, V8, Each. Part Number: VRE ...Did the 5.3 come with 243 heads? Of course, today’s 5.3 and 4.8 both have 243 heads that are factory-designed. 243 heads were included in the LS6 engine produced between …

87LC2. This is rarely brought up, but the combustion chamber design of the L92/Ls3 heads is superior to the 241/243 chambers. The cathedral heads use a "heart" shaped chamber where the square port heads use a "butterfly" shape. The butterfly design is said to improve tumble, swirl, flow, flame propagation, everything.

But, the combustion chambers are bigger than the 5.3 heads. You need to mill the 243 heads about .020" to keep the compression ratio the same. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow.On the other hand, TSP Stage 1 LS6 heads are $1500 complete and they glow about the same as the stock LS3 heads. One major difference is the ported 243 castings won't have much potential for better flow while the LS3s could still be ported. Both the ported 243 and stock LS3 heads should work really well with an LS9 cam or slightly wilder.BARE GM LS 243 HEAD - 4.8L, 5.3L & 6.0L. Generation III V8 cathedral intake port cylinder head. Casting 12564243. For truck, van, SUV and perfomance applications. Used on LS6, L33, L20, LH6, LY5, LMG, LC9,LS4, LH8, LS2, LFA, LZ1 engines. Generation III cylinder head for V8 truck, van, SUV and perfomance applications often called an LS6 head. It ...243's are extremely capable of good gains when CNC'd...I still use them right now. 2005 GTO QSM, 418" NaturallyAspirated ,Bullet Racing cam, 243 heads, 6speed, Kooks 1-3/4" headers w/cats ,matchported FAST 102,NW 102mm, 3.73 gears PB in 1/8th 7.76@97 on Firestones with 1.97 60'. Tick Performance tuned. 522 RWHP/501 RWTQ.Takaba certainly did not want to let go of his partner, Kenjaku, and the comedy act to come to an end. However, he realized that, just like a star, he had now reached his brightest point before ...Jun 3, 2022 · The 243 heads come with 1.7 - ratio rockers responsible for opening and closing the intake and exhaust valves. The configuration is different from the 1.8 ratios found on most other LS heads. The main benefit of this is that it allows for greater lift, which results in more airflow and more power.806 is the casting # of the heads . Its on the front corner . 806 is the worse flowing LS1 head and has perimeter valve cover bolts .They came stock on the 98-99 F bodys . 241's are a little better . I believe they came on 00-02 . 243's are the best of the 3 . 243's in stock , untouched form will add @ 20-25 RWHP over 806's and 241's.The LS4 is a 4th gen, 5.3 l aluminum small block engine that was used in GM cars between 2005 and 2009. They had cathedral port cylinder heads and used Active Fuel Management (AFM). The LS4 cylinder heads came with two casting series numbers - 799 and 243. The combustion chamber volume is 65cc.Guys I'm located in Biloxi, MS 39532. The Heads, injectors, and fuel rail have 40,000 miles on them, springs, cam, ported intake were installed at 30,000 miles. The combo made about 418/388 on one dyno and 397/374 on another in an 2006 LS2 M6. 243 Heads SOLD LS2 Ported Intake SOLD LS2 Stock Injectors $100 + Shipping & paypal LS2 Stock Fuel Rail ...

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Let's celebrate a hunting round that is aging well. Prior to the 243 Winchester's arrival, America's most versatile, light-recoil, "dual-purpose" cartridges for hunting varmints and deer were the 250-3000 Savage and 257 Roberts. Both pushed .257 caliber bullets of 87- to 120-grains in the neighborhood of 2,600 to 3,200 fps.The cost? Too much for the bang. If I didn't care about maintaining a stock-looking engine bay (painfully stock), I would go with AFR heads. Stock LS6:243 heads aren't worth purchasing (new) - IMHO. You CAN find stock LS2:243 heads in new condition for a very low price (~$600/pair). The difference is in the valves (LS6 valves are …Last updated on 05/06/2024. The LC9 engine is a 5.3L, Gen. 4, aluminum small block engine used in GM trucks and SUVs between 2007-2011. For marketing purposes, it was also known as the Vortec 5300. The engine specs and information listed here is for a stock LC9 engine. Mechanically similar, General Motors’ LS and LS-based …You will see 50+rwhp probably at same psi. 317/243 heads flow MUCH better than 862 truck heads. flow more at .400 lift than the 862's flow at .550 lift. Boost will also lover the bigger 2" intake valves. 243's with their smaller combustion chambers would be a better match. than the 317's.Thanks. 853 and 241 are basically identical. 853 was used on 99-00 LS1 engines. 241 was used on 01-04 LS1 engines. They both have a 66.67 cc combustion chamber (10.1 CR), 200cc intake runners, and 70cc (round) exhaust ports. The 243 head is the 01+ LS6/LS2 head.stock 243's are worth about 15 rwhp, with cam and headers maybe 20-25 rwhp at most. i was in the same boat decided to hold the 243's until next yr or longer and send them to cartek for a 2X job and mill then then they will be worth about 40 to 50 rwhp. somebody else on the forum will come along and give you some more advice from experience with stock 243's. good luck btw what cam will you be ...821/823 castings. im going to order ls3 heads but i would like to know the difference between 821/823 castings,i thought i read somewhere they were cast using a different process or something to that effect ,so which is better ls3 or l92 or is there no difference besides the map sensor. IBM 04/A4, #243 heads, Mild Blower cam by Comp (216/228 ...The 243/799 cylinder heads come with a 2.00" intake valve, 210cc intake runner, a 1.55" exhaust valve, 75cc exhaust runner, and it has a 64.5cc combustion chamber. The 243/799 3cc bigger combustion chamber might not seem like much but let's look at the factory Compression Ratio as seen here. And then compare it with the 243/799 cylinder head ...Katech logo laser etched on both ends. Note: Re-assembly and valve reconditioning not included. This program works on the following head casting numbers: 243, 799, 317, 035. Now you can get this porting service on your cylinder heads at an incredibly low cost! Simply follow this procedure: Remove the cylinder heads from your car, print a copy ... ….

On our Mast heads, the LS3 head offered both more intake and exhaust flow than the cathedral-port heads, resulting in an intake-to-exhaust flow percentage (372/261 cfm) of 69.89 (meaning the ...Aug 18, 2011 · 241 was used on 01-04 LS1 engines. They both have a 66.67 cc combustion chamber (10.1 CR), 200cc intake runners, and 70cc (round) exhaust ports. The 243 head is the 01+ LS6/LS2 head. It has a smaller 64.45cc chamber for more compression (10.5 CR on LS6), 210cc intake runners, and 75cc D-shaped exhaust ports.823 vs 243 heads The popular L6 243 heads have a smaller capacity (64cc), whereas the 823’s larger intake valve has a 70cc cylinder, promoting better overall flow within the combustion chamber. In addition, there’s some controversy among gearheads about whether the “swirl” ramp added to the 243 to improve fuel and air mix in the ...Jul 16, 2007 · Thanks. 853 and 241 are basically identical. 853 was used on 99-00 LS1 engines. 241 was used on 01-04 LS1 engines. They both have a 66.67 cc combustion chamber (10.1 CR), 200cc intake runners, and 70cc (round) exhaust ports. The 243 head is the 01+ LS6/LS2 head.45 posts · Joined 2006. #4 · Apr 12, 2010. I'll recommend TFS 215 heads and a 224/228 comp cam. A friend of mine has this package and I was really impressed. With a ported fast he made 450 rwhp and the car idled and drove great. It was actually a little tame for my taste, but sounds like what you're looking for.The 243/799 heads made more power than the 317's in back to back N/A, and boosted, dyno pulls on the same motor. Sounds to me like you've already convinced yourself the 317 is the better head, so I'm not sure why your on here asking. Besides, from your post, headers are too small, so the head choice may be irrelevant.The factory-built motor dished out about 430 horsepower right out of the gate, and the cylinder heads play no small role in that impressive output. The LS3 heads hit the flow bench. The LS3's 319-T5 aluminum alloy cylinder heads use 2.165 in (55.0 mm) intake valves, 1.59 in (40 mm) exhaust valves, and a 15 degree valve angle.241 vs 243 the 243 is a better head. Ported vs Ported the 243 is a better head. The AFR heads are 205CC intake runners. They do this to keep velocity up. Many porters go larger then this "225+" which can effect you TQ curve at lower RPM's. I'm using a set of 317's with 225CC intake runners that flow 310 at .6000. What did 243 heads come on, What did the 601's come on? Save Share. ... Better heads would be any of the 305 H.O. varieties that RB69SS396Conv mentions. (Basically, the heads that were used on the High Output 305's) Stock, they all have the "small-ish" 1.84 intake valves, and ~150-160cc intake runners. -601's have ~55cc chambers, -416 and -081 heads have ~58cc chambers., But these heads also saw duty on some 1962 and 1963 full-size Chevy passenger cars with the 300 hp 327. Those produced in the Tonawanda plant were exclusively used on those bigger cars. Flint heads saw duty on both full-sizers and Corvettes. The heads are quite easy to identify, as they sport an "X" underneath the #1 or #8 exhaust runner., 706 heads are very affordable. 706 heads are plentiful and easy to find. 706 heads have smaller chambers, so you don't lose compression. 706 heads are slightly superior to 862 heads due to how ..., The 243 heads are a type of LS cylinder heads that were originally used in the 2001-2004 LS6 engine. These heads are known for their high-flow intake and exhaust ports, which allow for improved performance and efficiency. Today, 243 heads are a popular choice for those looking to upgrade their LS engine's performance., Mar 29, 2024 · The 243 Heads are cast iron cylinder heads that have been CNC-machined to create larger intake and exhaust ports. The combustion chambers have also been machined to be smaller, which increases the compression ratio. While the 243 heads are not the newest or best option out there, they offer a great value for the price., RPO L99 and LS3 cylinder heads are aluminum with 68cc combustion chambers, rectangle intake ports with 257cc runners, D-port exhaust with 87cc runners, 2.165˝ intake valves and 1.590˝ exhaust valves. These heads can be CNC-ported to improve on flow and milled for higher compression. These heads are almost the same, but the L99 heads used a ..., The 862 heads are inferior to the 706 heads in terms of compression, and they don’t also flow well like the 243 heads because it doesn’t have other competitive features; however, depending on your car’s needs and budget, the 862 cylinder heads might be a good port for you., With that, we packed up our heads and shipped them off to Lingenfelter Performance Engineering (LPE). Lingenfelter's 243/799 CNC program opens the intake port (left) to 228cc and increases flow at .600-inch of lift to 320 cfm. The exhaust ports get opened up to 84cc, and the chambers stay at 65cc in the off-the-shelf configuration., RPO L99 and LS3 cylinder heads are aluminum with 68cc combustion chambers, rectangle intake ports with 257cc runners, D-port exhaust with 87cc runners, 2.165˝ intake valves and 1.590˝ exhaust valves. These heads can be CNC-ported to improve on flow and milled for higher compression. These heads are almost the same, but the L99 heads used a ..., 51 posts · Joined 2011. #1 · Feb 22, 2012. Are the 5.7L 243 Casting Number Cylinder heads Direct Bolt on for a 4.8/5.3? StrokerAce03;5114860 said: Basically its just a bastardization of parts to create an oversquare engine that should scream at high rpm and rev to the moon. BE DIFFERENT., C5 General - What years trucks/tahoes came w/243/799 heads - I need to scavange valve covers and ignition coils and brackets and ignition coil harness for next project. I just got for my 97 C5 243 ZO6 heads that came off from 02 ZO6 .The valve covers are perimeter bolt on mine and 243 heads are center bolt and coils..., You don't need it at 500hp. A 1-7/8" tube typically runs out of room at around 1khp. Your fine. As mentioned, the gains seen from porting won't be huge. The reason is everything is already working pretty darn good as is. It would take a few more radical steps to move north on power., JEGS LS Aluminum Cylinder Heads are the perfect replacement or upgrade for your LS-based engine. Starting with a new aluminum casting these heads are fully assembled with all new components including intake valves, exhaust valves, valve springs, retainers, guides, and seats. They are available in cathedral port and rectangular port designs to ..., 45 posts · Joined 2006. #4 · Apr 12, 2010. I'll recommend TFS 215 heads and a 224/228 comp cam. A friend of mine has this package and I was really impressed. With a ported fast he made 450 rwhp and the car idled and drove great. It was actually a little tame for my taste, but sounds like what you're looking for., Without additional relief for 50 million working parents, the economy could suffer even more. American parents stand to lose even more productivity—and their minds—as more school d..., The P heads have one more vertical bar. Also, the gt40p heads are simply the best flowing heads that ford ever produced for the small block Windsor motor. 1998 5.0, fitech efi, holley in tank returnless pump. 4R70W transmission with USShift quick 2 controller. 3.00:1 8" open rear end., Jun 10, 2008 · I did 3 mods at once: 1. 243 Livernois Stage 2 heads 2. Kook's LTs 3. Mild cam (TR 224/224 112) The gain from those 3 mods was 102 rwhp over factory. I debated the 5.3 heads vs. the 243s, was never able to come to a definite conclusion, so for the slight bump in compression I used the .040 Cometic gaskets., What Are 243 Heads? Also known as 799 heads, 243 heads are the best performing aluminum cylinder heads that were standard on 3rd generation GM LS6 & …, Intake and Exhaust Ports. The intake and exhaust ports on the 243 heads are larger than those on the 799 heads, which allows for more air and fuel to enter the engine. This can result in higher horsepower and torque output. However, the smaller ports on the 799 heads can provide better velocity and airflow at lower RPMs, which can be beneficial ..., C6 Tech/Performance - 243 Cylinder head question - I have someone who wants to sell me some cylinder heads. They have the 243 casting number, but on the inside of the head, it is stamped 5.7. I am not sure if these are heads for an LS6 or for an LS2 motor. I also have a part number of 12564825., Another thing to consider is the life span of the MTI springs. The stock GM springs are guaranteed for three years, or 36,000 miles but generally last the life of the engine. Would you have this assurance with the MTI springed heads. Below are some GM numbers for 243 heads as a comparison. Stock CNC'd LS6 heads I E.100 .200 147 111, C5 Tech - Need some input on Patriot stg 2 243 heads - Im looking at a set of low milage, used Patriot stg 2 243 heads milled to 59cc with the Patriot 650 dual springs. My car is a 2003 Z06 with long tubes, fast 90/90 and a comp cam 230/232 592/595 111 lsa. I realize that AFRs and Trick Flow heads are probably far..., Jun 13, 2015 · The early 5.3's had either 706's or 862's unless it was a "L33 HO 5.3" which only came in some trucks. My 04 Rainier has 862's, my 02 Avalanche had 706's. The 243/799 heads are one in the same, excluding the 243's that came on the LS6 motors as they had hollow stem exhaust valves and better springs, but everything else casting …, Dec 22, 2010 · 821/823 castings. im going to order ls3 heads but i would like to know the difference between 821/823 castings,i thought i read somewhere they were cast using a different process or something to that effect ,so which is better ls3 or l92 or is there no difference besides the map sensor. IBM 04/A4, #243 heads, Mild Blower cam by Comp …, May 24, 2012 · I've heard very good things about the sodium filled valves, and that they really make the difference between the Ls2 and Ls6, but they're not worth the extra $200+ dollars you're going to spend on the heads. Sure, they might be awesome for me, but when i'm getting a hell of a deal on LS2 243's, i'm gonna go that route. Just my 2 cents., All other manufacturers of rifles offer this caliber. The .243 Winchester represents a successful effort to develop a light deer rifle caliber that could hold its own with the high-velocity .22s for long-range use on small targets and still be adequate for larger animals. The .243 does this job well. It eliminates the need to own two different ..., This also means that they are usually cheap to collect or replace. 706 heads tend to be more popular than 243 heads with those who run naturally aspirated engines. While they don't have the same size combustion chamber they also don't have the tendency to lower the compression ratio and reduce horsepower. When looking to replace your heads ..., Another thing to consider is the life span of the MTI springs. The stock GM springs are guaranteed for three years, or 36,000 miles but generally last the life of the engine. Would you have this assurance with the MTI springed heads. Below are some GM numbers for 243 heads as a comparison. Stock CNC'd LS6 heads I E.100 .200 147 111, 3012 posts · Joined 2008. #1 · Apr 14, 2012. I have a 2004 Aluminum 5.3 with 70k miles that has 862 heads on it. I also have a set of 243 heads off of a 2009 Aluminum 5.3. Which heads should I use? I've been told the 243's flow better and the 862's supposedly raise compression .5 a point., The 243 vs. The 799 Cylinder Head. As you have most likely caught on by now, these two cylinder heads are practically the same. The main difference between the 243 and 799 cylinder heads is that the 243 was used on older engines from GM Research, while the 799 has been used on newer engines from multiple manufacturers., 1232 posts · Joined 2010. #2 · Jun 29, 2010. The originals from the 60's and early 70's didn't have the bowtie, but I believe the later ones did. Not sure on that. Those heads were on the L78 396's in Nova's, Camaro's, Chevelles, etc. and the ZL1, L88 and L89 427 in Corvettes. Yes these were fairly rare from the factory., Compatible Engine Type. Anyone who is considering getting either the 799 or 243-cylinder head needs to know about their engine compatibility to make sure they …, Takaba certainly did not want to let go of his partner, Kenjaku, and the comedy act to come to an end. However, he realized that, just like a star, he had now reached his brightest point before ...