Start with heads. Edelbrock's Aluminum 2.02 1.68 or larger valves - Large valve(2.02/1.60) "J" heads ported (need the extra flow of porting)
magnum heads flow well also but are prone to cracking. The 576 castings are better.
A roller would be the cam type to use as your going to have to buzz this engine some to get what your looking for, At the least 6K & should be around 6,500
however this cam will get you to around 440hp Cam specs: 216/228-degrees duration at .050-inch valve lift,.484/.512-inch lift with 1.6:1 ratio rocker arms
Compression ratio needs to be at least 10:1 & should 10.5:1
Street. Edelbrock performer & 750dp
15/8 headers w/free flowing X piped 21/2" dual exhaust.
So that's about it. Have you considered stroking this engine to 408?