MillersSS

iTrader: (1)

This is my first ls build, and I need some advice on heads for my 04' lq4. This is what I want to do, I wanna make at least 425 rwhp. I'm running a 231-237 tsp cam, ls6 intake, underdrive pulley, pacesetter lt's, and a ported tb. I cant afford to spend alot on a set of heads, about 1500.00 max. Really want at least 10.5:1 comp. I've looked into having my 241's and 317's ported, and milled, but it looks like buying some patriot heads would be cheaper, especially since I could sell the other heads to offset the price. What do you guys think about using the patriot 5.3 heads? They sell for around 1100.00 fully assembled, with bigger valves already installed. I know they would get my comp. ratio up, but will they flow good enough to make the 425+ rwhp?

98TA6.0

iTrader: (42)

just use the 317s. those heads are awesome and flow like 243s. just get them milled and you could even find a machine shop to CNC port the set. you'll save money and have a that will do great on the street. i use 243s on my LQ4. got them CNC'd and used Isky Double valve springs. only spent 900 bux on the set after all the work.

PREDATOR-Z

On LQ4 ~6.7 dish piston, 317s would have to be milled to ~62 cc for 10.5 SCR (stock gasket). That is a 9cc mill or ~.006x9= ~.054 mill

That is too much mill IMO.

Better get a set of LS2 243s or 799 castings with a .015 mill. That would be my choice.
You can find them cheap as take offs and get them CNC'd with a nice VJ and proper springs.