Heads, intakes and carbs - Build my 306

If you're talking about 380+ rear wheel hp then you're gonna have to really build a nasty 306 to get there. You're gonna need big heads, at least 11:1 compression and i'd recommend a custom cam to squeeze every last bit out of it. My buddy's 347 just dynoed 385hp/400tq with Edelbrock Victor Jr heads (2.05 intake valves, 1.60 exhaust), a Holley Systemax intake (it's EFI) and a custom cam with .628 intake lift and .585 exhaust lift. He made awesome torque with that cam but i think with a 306 you're gonna have to give up some bottom end to reach those hp numbers. The dyno tech said to give it a few thousand miles of break in time and change to synthetic and bring it back and it'll make 400hp.

If you're gonna supercharge it later, get forged pistons now. It's all gonna be a lot easier if you can squeeze a stroker kit into your budget.