So, what parts do already have? If you have the 220 heads already, maybe consider a 383-388 stroker. Will make more torque and if you stay with a smallish flat tappet cam, in the range of 250-260 duration @ .050 and .550-.575 lift, will perform well in a heavy car like yours. I built one a few years back and he runs 11.40's in Denver and I think he's run 10.60's in Topeka in a 3200 lb Camaro with 4.88's and a 29.5 tire......just a thought. Just don't get caught up in the "big heads, big cam, big carb" thing, because you won't be happy with it.
Johnny