318 f.a.s.t class , oem stock appearing
Hes inspired by FAST but it's a street engine if I got it right.
You definitely can do what you want you can build a mean 2bbl manifold 318. 400-500 hp though is gonna be expensive. The more powerful you go the more restrictive the 2bbl and manifolds will be so under 400 hp they will probably eat 50 hp if you go 500 hp they will probably eat 100 hp so you'd have to build a 600 hp engine to get 500.
I'm talking in general terms this ain't exact science.
So a 390 kit, 10:1 CR, ported out EQ's with a 360 2bbl intake with big block carb and custom 280 ish hydraulic roller. Would probably get you somewhere you want to be and your a headers and 4bbl swap away later if your not happy.
I'd use the 360 intake ovrr the 318 no matter what 2bbl you run the late model guys around here say the dyno more then the eddy performer.