Regarding the switch to the Webers - I don't know. The general assesment around here would suggest an increase in tq. with a decrease in hp. A friend on this site has a stroked 427 center oiler (454 ci) built similiar to ours with webers and has 575 tq & 526 hp. with 10.5:1 compr. ratio. Even with the cubes he's way off your hp #'s and also a full point above yours in compression. If I were you I'd swap 'em out because the noticable difference will be minimal but with killer looks as an added bonus.
Here's a picture of my car with Webers from behind.
