Heads&Cam or Force Induction
But in an other wise stock engine the MS4 should be fine, it's not as big as a Trek and that fits without flycutting. But I will admit some aftermarket heads will require flycutting. Do you know what heads you friend has?
I made 513rwhp and 457 rwtq with my H/C setup.
H/C with every bolt-on is about the same cost as a procharger.
I love my ungodly sounding H/C setup.... Sounds like good ol' fashioned American Muscle!
https://ls1tech.com/forums/generation-iii-internal-engine/541723-h-c-install-almost-done.html







