So you might have some idea what the 6400 cam will do..........

Just built a .030 over 400 using the 6400 camshaft. Used the 346 heads with some minor porting so they flowed 250 cfm @ .500" lift. The engine was 7.515:1 compression and with the factory 2bbl carb and the factory 2bbl cast iron intake and dyno headers it made 371 lb-ft and 285 horsepower.

Went to the shelf and grabbed a 383 Street Dominator intake and the old reliable 950 Quick Fuel and it made 397 lb-ft and 361 horsepower.