I want to get the Patriot Performance ported 243s or ls6 style stage II heads(62cc combustion chamber, 2.02, 1.57 valves) with the f13 cam. My car is a daily driver. After heads/cam I would like to be able to dyno at around 425 rwhp, just to give a general idea of the power output. I don't want to sacfifice low end torque, but mid range and top end could use a little giddy-up. I want to be able to beat a z06 vet in a 1/4 run. Are the valve sizes and combustion chamber sizes right. I've heard that Patriot heads have had some ptv clearance issues.

 

Should not be but talk to the guys at Patriot. F13 will definitely sacrifice low end torque though. You will want to mill the heads to get better DCR with that overlap and you need to be precise in how you go about it so talk to patriot or futral to plan your upgrade.

 

Thats almost exactly what I'm doing for my upgrade. Instead of buying heads thou, I'm porting stock 241 heads. I put in the same valves you mentioned, and I'm just waiting to get my car out of the body shop so I can start on the mechanical work.

I've milled my heads 0.01" to up my compression a bit and according to futral, If I use a stock thickness gasket, I shouldn't run into any ptv issues. I'm not sure how different the patriots are, but check with me in 2 weeks and I'll let you know if I've had any issues, since we have almost the same build.