This maybe a stupid question but I don't know the answer. What is the difference in a ls1 head and a ls6 head? I got a gm performance catalog and it shows that the valves are the same size. 1.55\2.00 on both of them.

 

There are differences in the curve and floor heighth of the ports as well as "D" shaped ports on the exhaust ports. The compression ratio is different as well because of the combustion chamber size.

 

the ls6 heads flow allot better.

 

Well I appreciate the info.

 

How much better do they flow?

 

Here ya go...

http://www.smokemup.com/tech/ls1.php

 

ls6 241 better then a 243 head off a ls2 or same flow/comp???

i also have never looked into this-

 

actually,,,241's (LS1) with the right PNP job can out flow 243's (also PNP'ed) up to about .400 or so,,,,there are threads out there, do some searchin, you'll find em. Does this mean that LS1 heads can be better than the 243's?? hell no. But 241's rock,, if your broke, and already own em.

 

stock ls1 heads flow around 240/245 cfm and stock ls6 heads flow about 265/270. ported ls1 maybe up to 300 cfm at .600 and ported ls6 over 320 cfm. my TSP stage 1 flow 307 cfm at .600 . now stock vette ls6 heads come with hollow stem sodium filled valves (light weight) mine have steel valves (budget). hope this helps. car craft or hot rod mag had an article gen III head basics. pm me a fax # and i'll send it to you.