The 243 heads came on the powerful LS6 engines from 2001 to 2006. Although the heads were initially made for C5 Corvettes, they later found their use in engines like the truck-spec LQ9 and LQ4. The LQ4 and LQ9 had 6 cc larger combustion chambers. LS6 was also used in some Camaros and Pontiac GTOs. The 243 heads are cast out of aluminum alloy ...The two types of heads, 241s and 243s are found in many vehicles. The combustion chambers for each of these types differ slightly: 243 heads have an internal volume of 65cc while 241s have a 67cc size. Due to this difference in size, the compression ratio for 243 heads is higher than that of 241s, meaning that more power can be …C5 Tech - LS6 valves vs stainless aftermarket in 243 heads - Curious if you guys running 243 heads keep the stock valves or replace them with aftermarket that might help flow. Looking to pick up a set of 243 heads needing hardware and work them over myself. I imagine the LS6 valves are not undercut like the stainless...Aug 6, 2020 · 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 heads are often called LS6 heads because they were found on the 2001 - 2006 LS6 engines. The 243 heads have a D-shaped exhaust and cathedral-shaped intake ports. The cylinder heads combustion chamber is smaller than the earlier cylinder heads fitted on LS1 engines. 243 is also more efficient than the earlier heads found on LS1.Jun 5, 2010 · Price wise both companies are very close to each other. TEA Stage 2 Heads $1320 w/ 2.04/1.57 valves and dual springs. AI CNC Heads are $1245 w/ new stock valves and dual springs. It seems like the TEA has an obvious advantage in flow with the 2.04 intake valves but AI does not have any options for larger valves on their website.4.8l with 243 heads. Jump to Latest Follow ... LS6 heads, 232/234 592/595 111+4 Kooks 1 7/8, Super 40s cat back, K&N FIPK Lucas 42lb injectors BOP Talon and BOP line/bleeder ... Come discuss mods, horsepower, engine specs and more! Show Less . Full Forum Listing.Usually, conventional small-block heads did not flow nearly as much air as the best factory cathedral port heads. The 243, 799, and 317 castings of these cathedral port heads could flow up to 250 cfm which was a major improvement over what preceded them. But the LS3 heads took this concept even further and were capable of an impressive 317 cfm.C5 Tech - Need some help with 243 heads.. Ques. - Are the 243 heads off a 2010 silverado the same as the 02-03-04 ZO6 243 heads..They say they will fit the LS engines.No 243s or 799 have the casting defect that I've heard, it was pretty isolated to the castech only 706's on gen III 4.8/5.3's. There are 2 other sets of 706's that are not affected. The early sand cast heads come as 862s and 706's, and a die cast 706 that isn't made by castech. 16 posts.243 04 up LS6 aluminum center bolt 5.7 ***These castings were also used around 05 in truck applications*** 862 99 and up 4.8-5.3 Truck heads 706 99 and up 4.8-5.3 Truck heads 799 05 and up 4.8-5.3Truck heads ***reportedly came on a few corvette's too*** These are basically 243 Heads 873 99-00 LQ4 6.0 Iron center bolt headsSince then, the lampshade on the head has come to symbolize the obnoxious drunk trying to be funny—and failing. In 1938, a columnist described alcoholic actor John Barrymore as "at any moment ...GM Engine & Exhaust Performance - lm7 with 243 heads - hey, I am new here and have been looking at some of the posts. I am going to be pulling the heads on my 03 sierra 5.3 lm7 and was considering putting on some 243 heads with a .040 cometic gasket to bring the compression to 9.8. my concern was with torque, I use...Received 9 Likes on 8 Posts. Advice on 243 heads build. Hey All, Hope everyone is doing well! I cleaned my garage this weekend and got excited about starting a new project. I have a set of 243 heads sitting here that I'd like to upgrade. They only have the valves and springs on them and I'd like to replace those. I have a base ls1.Did the 5.3 come with 243 heads? Sometimes referred to as the LS-family , engines such as the 5.3 and 4.8 come equipped with factory designed 243 heads. This design was implemented by General Motors starting in 2001 all the way up until 2006 when they stopped production of their LS6 engine which also featured these 243 heads. If you want to ...Feb 21, 2018 · Chevrolet LS rectangle port heads need at least 4.00 bore. 5.3 and 4.8 are 3.78". LS7 heads require even larger. All 4.8s, 5.3s, and 5.7s came with cathedral port heads. Like mentioned, the square port heads were not put on any engine with a bore smaller than 4”.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.I know 243's are good but didn't know if 862's are any good when they're right in front of me. They won't flow as good as 243 but you'll have better compression vs 243. You can have them ported for a reasonable price and have a good valve job done on them to make them perform. They'll never be rock stars but they'll do fine with that cam.Last updated on 05/06/2024. The L92 is a 6.2L, Gen. 4, small block engine used in GM luxury trucks and SUVs between 2007 and 2008. For marketing purposes, it was also known as the Vortec 6200. The information listed here is for a stock L92 engine. Mechanically similar, General Motors’ LS and LS-based Vortec engines wound up on almost every ...The L33 is a 5.3L, Gen. 3 small block engine used in GM trucks between 2005 and 2007. Although it is a truck engine, it used cylinder heads closely related to the LS2 and LS6. The engine came with flat-top pistons for increased compression, and has a unique camshaft. For marketing purposes, it was known as the Vortec 5300 H.O.The 243s can be done up great, just under or even with the flow of built ls3 heads. Its not out of the realm of possibilities to hit 500-525rwhp on a fully built stock internal LS2 with worked 243s through an M6. Google Advanced Induction and what they do with 243 heads for around a grand.doing math an saying you have 2cc worth of valve notchs i got you around 12-1 comp wise with the 58.5 in for head cc an pistons out .006..with the 60cc 243s i got you at 11.8-1 with 2cc notchs,.006 out and .040 gaskets..hope this helps. I had them actually cc'd after I removed em.. 61.5.. Steve. 408, th400, 1100rwhp..The 317 heads featured ports that all but duplicated the LS2 243 heads, meaning they were cream of the cathedral-port crop in terms of airflow. The 317s did differ from the 243s in that they featured much larger (and less efficient) combustion chambers. Where the stock 243 heads featured 65cc chambers, the 317 heads featured 72 cc …243 Heads/Cam Dyno. 8642 Views 94 Replies 20 Participants Last post by Perdieu, Jul 5, 2006 Jump to Latest Baaa ...Upgrade your LS1 or LS6 engine with our Remanufactured CNC Ported 243/799 Cylinder Heads with .650 Springs and 2.02/1.59 Valves. These high-performance heads, designed by Chevrolet, are meticulously remanufactured to exceed OEM specifications, ensuring top-notch quality. These CNC Ported LS heads, part number ALL-65056PC, fit engines within the ...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.Apart from 823 heads, you can easily come across 821, 799, 243, and 706 cylinder heads. I have tested these to summarize this rundown for you, so check it out! 821 vs 823 Heads. Basically, this couple has the same structure yet different valve and spring technology.Did the 5.3 come with 243 heads? When it comes to the 5.3 engine, it is commonly equipped with 243 heads. This has been the standard for many years and is also seen in 4.8 engines as well. For example, the LS6 engine designed between 2001 and 2006 came with these factory-designed 243 heads.TEA Stage 2 Heads $1320 w/ 2.04/1.57 valves and dual springs. AI CNC Heads are $1245 w/ new stock valves and dual springs. It seems like the TEA has an obvious advantage in flow with the 2.04 intake valves but AI does not have any options for larger valves on their website.Jan 21, 2022 · 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 ...This listing is for a rebuilt GM 5.3 liter V-8 cylinder head. These heads come on GMC and Chevrolet trucks and SUV's. For other models see our store listings. This head is completely rebuilt. It has been pressure checked for cracks and resurfaced. Guides and seats have been replaced as needed. New VITON valve stem seals have been installed. All heads are given a valve job. All valves have been ...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 …The .243 Winchester (6×52mm) is a popular sporting rifle cartridge. Developed as a versatile short action cartridge to hunt both medium game and small game alike, it "took whitetail hunting by storm" when introduced in 1955, and remains one of the most popular whitetail deer cartridges. It is also commonly used for harvesting blacktail deer, pronghorns and mule deer with heavier rounds, and ...Aside from the casting number, they have distinctive D-shaped exhaust ports. 243 castings are harder to come across and are sometimes called LS2 heads. On the truck side, these would be 035 or 317 ...The two types of heads, 241s and 243s are found in many vehicles. The combustion chambers for each of these types differ slightly: 243 heads have an internal volume of 65cc while 241s have a 67cc size. Due to this difference in size, the compression ratio for 243 heads is higher than that of 241s, meaning that more power can be generated from ...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 ...The LY5 engine is a 5.3L Gen. IV iron-block engine used in GM trucks and SUVs between 2007 and 2009. For marketing purposes, it was also known as the Vortec 5300. The information listed here is for a stock LY5 engine. Mechanically similar, General Motors' LS and LS-based Vortec engines wound up on almost every branch of the GM family tree ...DualQuadDave Discussion starter. 1019 posts · Joined 2017. #1 · Oct 7, 2018. Hi all, I am looking for info/opinions on doing a big valve 243 head. I have researched and about 2.04 is max size for stock seats. I have a motor that I want to do a 2.08-2.100 valve and shoot for 330-340cfm int flow. Motor is 4.005 bore, .620 int lift.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 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 ...MattGTO said: I just recently put together a stock LS1 short block with new bearings, rings, honed cylinders, etc. I put a set of stock 243's on it with all comp trunions, comp springs, and pushrods. I also put an MS4 cam from texas speed in it, .649/.600 239/242 111.5 LSA 110 ICL are the specs. Has ebay long tube headers on it and a K&N CAI.What did LS 862 heads come on? It is no wonder that the 862 heads are so popular among General Motors' LM7 engine owners , for these cylinder heads pack plenty of power and a great design. Crafted from aluminum with a 61cc combustion chamber volume , these cylinder heads feature a cathedral-shaped intake port and an oval exhaust port .With a massive online catalog, you can easily view our inventory of Chevy 350 cylinder heads. The knowledgeable staff at CCH would also be happy to help you choose the cylinder head that is right for your needs. Contact Clearwater Cylinder Head Inc. toll-free at 1-800-572-1963.706 heads, also known as "706 cylinder heads," are a specific type of cylinder heads commonly used in engines produced by General Motors (GM), specifically in their LS series. These cylinder heads are quite popular among engine enthusiasts due to their compatibility and desirable features. The name "706" comes from the casting number ...Compression Ratio & Combustion Chamber Size. I'm looking to install a set of 243/799 heads on my 5.3. The stock heads have a combustion chamber volume of 61.15cc, and 243/799 heads have a volume of 64.45cc. My stock compression ratio is 9.5:1. I already know that I need to mill the heads .007" to lose 1cc of volume.The 5.7L LS6 is the most powerful Gen. 3 small block engine as it came from the factory. It is an improved version of the LS1 produced for the 2001 Z06 Corvette. The LS6 powered the 2001-04 Corvette Z06 and the 2004-05 Cadillac CTS-V. Mechanically similar, General Motors’ LS and LS-based Vortec engines wound up on almost every branch of the ...The LS2 is a Gen. 4, 6.0L, aluminum small block engine. The engine specs and information listed here is for the stock LS2 used in GM passenger cars from 2005-2007. Mechanically similar, General Motors' LS and LS-based Vortec engines wound up on almost every branch of the GM family tree: Chevy, Pontiac, GMC, Cadillac, Buick—heck, even Saab ...Factory has the 862 heads. I’ve been offered a 5.3 block with 243 heads on it for $300. Would the stock 243 heads work better on it than the 862 heads? Obviously they need to go to the machine shop to be looked over but without any alterations to the stock form, which is the better head? Engine is stock other than cold air intake.If you are asking, “What did 243 heads come on?” The 243 heads were typically found in GM’s C5 Corvette; however, it was later ported and now found on engines like truck specs LQ4 and LQ9. The LS6 was designed to work with the Corvette’s titanium exhaust system in order to deliver extra power.