A 440 A-Body... that can handle?

i set up my 74 duster to handle decent, its got a bb and viper 6 speed. gets 20 mpg on the highway. i think it would do a lot better with more compression and a more efficient combo.this was just to get it rolling. it handles pretty damn good for what it is. all iron bb, stock power steering. no fiberglass parts. the 400 got a hone, summit cam, rings, tti headers, performer intake, and a holley 750. the front end has 1" torsion bars, 11 3/4 cordoba rotors, moog offset upper control arm bushings rms hiem jointed strut rods, and a tube hellwig sway bar. the back is just some hd espo leafs with an explorer 8.8" rear with 12" discs. kyb shocks and 17" mustang bullits all around. the bb is cool, but the original plan was a 5.7 hemi, and im rethinking that again.