i'm not a fan of superchargers or nox. i do like large engines. i would go with a 460 for get the 390 it;s a good engine but would not be my choice for a hi-po engine. i have a 429 that displaces 494 cubics. has a mild torquer type cam and offy intake with a 750 carter afb, police interceptor heads.(STANDARD heads with cobra jet valves,polished chambers and ported and polished exhaust.) headers in a 1969 galaxie sportsroof. the car is a strip model. only weights 3400 pounds. no p/s,no p/b,no a/c. and factory 4-speed. never aproblem . no maintance headaches. i bought it new in 1969. 429/4-speed. just my suggestion. i'm was a detroit deisel repair man and worked on 4-71,6-71,8-71,and 16-71's. they wear out in due time.