blue98Z

iTrader: (29)

Thinking about buying some 241 heads and was just wanted to know if they also are the LS6 heads or not? If not how much different are they from the 243 heads? BTW, if I get the 241's I'll be getting them CNC P&P. Thanks for the help. Josh.

98camaroLS1M6

iTrader: (35)

241s have a 200cc intake runner versus the 243's 210-215cc. 243s flow 240-250cfm stock, and 2002 241s flow low 230s. If you want a low-end go with 241s, and if you want more top-end go with 243s-that is if you decide to port them. Stock vs. stock unported- I'd go with 243s.

Azrael

iTrader: (10)

I would echo exactly what 98camaroLS1M6 said, but to answer your question the 241s are the LS1 heads from Late MY 2000+; whereas the 243 are the LS6/LS2 castings.

blue98Z

iTrader: (29)

So does this mean the 241's aren't any better than the 853's I have now? So I guess I need to find some 243's. Thanks for the help.

98camaroLS1M6

iTrader: (35)

without any work, not really.

blue98Z

iTrader: (29)

Well I guess I'll just save that $150.

Kraest

iTrader: (3)

241 = Ls1

243 = Ls6

1997bird

iTrader: (2)

Check with Jason at Texes Speed & Performance, they had some CNC 853 casting heads on sale here not to long ago. You can buy them bare or assembled with their 2.5 program. You might check with them soon as they are supposed to be porting my heads this next week(I had to wait until they were running this CNC program again).

Azrael

iTrader: (10)

241's are better than their predecessors, mainly because of the casting method.

jetblast

mine are 243 ported 255/85cc runner size, there are 2 different castings one better than the other. look for the v shaped mark just under the spark plug holes, these are the better ones, semipermanet mold casting process.

A502slo

iTrader: (4)

Can you get 241 6.0l heads??

chriswtx

iTrader: (5)

My stock 241 heads did pretty well. 398RWHP/372RWTQ with a small 224/224 115LSA cam, 1 7/8" headers, on my 2004 vette..As good as most camed Z06s with LS6 heads...But if your buying CNC heads, go for the LS6 with the smaller combustion chamber to up the compression...

GuitsBoy

iTrader: (4)

I believe that was a fallacy in the book. I believe all 241 and 243 heads used the SPM process. Every 241 head ive ever seen has the V shape. I also believe the 853 and 241 heads have the same port shape, the only difference was the move from sand cast to SPM.

cam1999

243 's have Hollow stem Intake valves and Na filled stem for the Exhaust valves!

GuitsBoy

iTrader: (4)

Only the LS6 version of the 243 heads. The LS2 243 castings came with standard valves.

jetblast

i won't argue with that statement but there are 2 casting processes, so visually how can you tell which one is which?

GuitsBoy

iTrader: (4)

The triangle under the spark plug holes. Also, the cast surface is much smoother on the SPM.

jetblast

also the gmpp 243 cnc ported heads came with the upgraded valves and sprins , found out through lingfelter that this heads are cnc ported by them for gmpp.