I did the same thing to my 76 Volare in 1988, I used a 440, Headman E body 2" headers and fabbed solid motor mounts. The car was new enough at the time I was able to get new quarters and a grill from mopar, with a little trimming on the front i can get a 30 x 10.5 to fit. If you want to save about 300 lbs make bumper brackets to replace the crash bars and energy absorbers at both ends.

I got my Volare for $150 from the back row of a chevy dealer, 73k on the clock.