ss4luck

... what would you do?

Car is currently FBO SBE LS6, A&A stage 2 blower Cam, V3T trim w/ 3.4 and meth. It made 670 last time on the rollers and I'd like to squeeze a bit more out of it.

I figured I could have my 243s out to be CNC'd or but some others and sell and sell my 243s. I have a fast 90/NW90 sitting on the shelf to install when the heads go on as well

winters97gt

Those untouched 243's have made 1000+rwhp with a YSI on a 347. I'd go ahead and put that money away for either a new headunit or a built bottom end.

winters97gt

If you're running the stock balancer, add a flip(direct/secondary) drive to it, pulley down to a 3.125 or 3.25 pulley. You'll pick up 75hp with those mods. Thought you had an SI. The t Trim is good for 800+ with the right combo.

ysb02

I'd keep the heads and port them at most.

+1 on a smaller pulley. Just spin that head unit to make the power.

Drewstein

Heads on FI are generally a poor investment. If you want more flow add boost.