jrz28

I have a 99 Z28 m6 with hooker lt's ,ory, flowmaster exhaust and slp airlid so far.I recently bought a ls6 intake and a cam (218 234 .60x .59x 111+2 lsa) to do a upgrade. Want to find some heads so i can do all at one time. What would be better the ls6 heads or the 5.3 heads? And what is the difference between them?

King Nothing

iTrader: (9)

5.3 give more compression but the LS6 243's flow better and you can bump the compression a bit with a different gasket

SAPS

218/234...that's a BIG split!

sidewayz28

iTrader: (24)

243s will bump your compression up to 10.5:1 if im not mistaken.. with a stock MLS gasket
and yea.. whats the deal on that cam?

jrz28

Thanks. I bought the cam from a guy I know. He had it in his 2002 camaro ss. I know with the cam and bolts on it dynoed 408 hp/396tq.

sidewayz28

iTrader: (24)

thats a decent amount of torque.. i dont think ive ever seen a cam with such'a split

SOMbitch

iTrader: (8)

243's IMO.....

jrz28

I think he said it was a cheaTR cam . I've seen cams with a split like mine in the thunder racing website.

King Nothing

iTrader: (9)

close to a cheater cam and i'm guessing yours has a high LSA, perfect for supercharger applications

sidewayz28

iTrader: (24)

stock for stock go with the 243s

SOMbitch

iTrader: (8)

For SURE stock for stock as the 243's flow about 30cfm more at .600. Even both ported I think they are a better head.

And the compression bump is not as much as you think because once they open up the 5.3 chamber for the bigger bore 346 they are 63cc and some change. I measured my TSP 5.3's after they came off my motor so this is not heresay.....

armyboyatc

iTrader: (29)

I run the ported 5.3 heads on mine and I DARE a car with LS6 heads to step up. Ha I say this because I have had some work done to mine and I love them. The compression bump helped my car out but it worked good with my combo. LS6 heads are good heads though.

King Nothing

iTrader: (9)

i'll step up at the end of the year when my planter box is running lol are you running a cam also?

TooLateVTEC

iTrader: (2)

243's no doubt.

Get them milled, ported and some bigger valves and go walk all over army boys car LOL

sidewayz28

iTrader: (24)

ok heres my beef: if you FIND 243s with sodium filled valves why would u swap them out? doesnt a lighter valve train = mo' betta'?
but i agree, i wish i would have gotten my 243s ported but i didnt have the cash at the time.. so their flat out stock