oversized valve ls1 heads or ls6 heads

[migsk8]

ok so before i waste my money on things i dont need, what could make more hp/ be cheaper

buy ls1 heads and build those, as in oversize valvesORbuy ls6 heads and just strap those suckers on

what makes more power outright?

p.s. this question is already on ls1 tech, just nobody has replied yet

[cnichols]

I plan on buying some 243 heads from an 02/03 Z06 and just throwing them on. Not sure if they'll make more power, but for the money, I know they work well. They also come with lighter, hollow stemmed, sodium filled valves that allow for higher revs.

[migsk8]

i bought that book i was telling you about, the ls1/ls6 builds, in the first chapter it say nothing good happens till chapter 5 or so. so im still not sure what 243 heads are? lol im just guessing ls6 heads? then if ls6 heads are 243 heads, then whats ls1 heads?

[Ari G]

Get the Ls6 intake and ls6 243 heads or 6l 317 and boost it

[migsk8]

Get the Ls6 intake and ls6 243 heads or 6l 317 and boost it

oes anybody know what makes more HP ?

[cnichols]

If you already have a complete longblock, don't mess with the heads for now. If not, find some complete 243 heads (243 is the casting stamp on the LS6 and LS2 heads). They will make more power than 317s because they will raise the compression ratio, whereas the 317s will lower it. People use 317s on a stock short block sometimes when boosting it so it is more forced induction friendly.

Just do some searching on LS1tech for very detailed info...but you will make plenty of power on stock LS6 heads and a healthy cam.

[migsk8]

actually that book i was telling you about, you seen chapter 6 ? its how to add 100 hp without heads pretty much :]

[Chris Gage]

I know this is old but I will answer this question for any future reference.

ported/polished ls1 heads will flow very close to ported polished LS6 heads. Its all about the port work. Advanced Induction, Texas-speed & performance, AFR, TEA all are very reputible for there programs. I would honestly send your stock heads to one of the listed above and tell them what the purpose of the car is, what type of cam you plan on running, what to of power you want to make.

Once the LS1/LS6 heads are cnc'd and polished, there is minimal difference's. The flow numbers will usually be between 305-315 @ .600 lift on a 3.905 bore. A ported 98 head will out flow a stock LS6 head. The best option to go with is a ported/polished 243 head (if you are not building on a budget), but you can not go wrong by any worked LS head. If you have the 97-98 perimeter style head, it may be best to stick with those as you will have to buy new valve covers and coil brackets to run a LS6 head.

Here is a great write up on how to make 500rwhp with a H/C/I 346 LS1. This write up should give anyone the base knowledge needed to build a combo that works as far as knowledge about the heads, cam selection, intake, and custom exhaust set-up

http://www.ls1tech.com/forums/....html

[migsk8]

sweet, looks like i have some reading to do

[Chris Gage]

sweet, looks like i have some reading to do

Any LS1 questions you have... feel free to ask.

[migsk8]

Any LS1 questions you have... feel free to ask.

ok will do, i haven't put much thought into it since im trying to get my s14 to look cleaner but you're the person im gonna email as soon as i have a question