HRHohio

Essentially it comes down to how much hp can your setup handle. Getting there you have options... high boost / low compression, or lower boost / high compression. Dropping your compression gives you more tunability but decreases your "all motor" performance (i.e. when not in boost). Keeping your compression higher allows you to take advantage of your build while not in boost, but limits the tunability by narrowing your boost range (i.e. 0-7 psi vs 0-18 psi). I think the best bet would be to port the heads to increase flow and drop compression down to 10.5 or so. This gives you a nice balance between the two. This is near stock compression for LS1 motors. Many people run 10 psi on stock motors, myself included. Having forged pistons allows you to push it up a bit. I think if you got a Methanol/water injection system, you could probably push it to 14 psi safely @10.5:1 and get into that 650-700 hp range. Just my opinion. Methanol/water will give you the most bang for the buck at this point when it comes to mods. Everything will depend on your tune.