Best bet on rear suspension?

For my '70 Duster, I'm planning on running a 400 big block with manual tranny..... The rear axle will be replaced with a ........ good question.... Don't have one sitting around, but have my eye on an 8 lug truck rear axle sitting around just down the road from me, I think it may be a Dana 60.... I need to get a better look at it though.... Yes it will need to be narrowed, but heck.... No one has anything close to me, so... That is, as far as I've seen.... Anyway, car will be on the street. Want be a monster, just something fun to drive. Probably want be on the track. Originaly I was thinking of getting the SS springs, spring relocation kit, widening the wheel wells about 2 or 3 inches.... Not sure though.... And run a nice shock. But after reading different posts about things, now I'm just not sure... Off the line it should hook, a little spin is fine, but would like it to be limited.... Tire size is undetermined. Gear ratio is also undetermined. Heck, only thing that's pretty much for sure is the 400 and A-833..... Oh and the '70 Duster.... I'll leave it at this, what would you suggest? Ride height, if it's a little taller in the rear than factory, then that's fine, but as I've read it in other posts, I don't wanna be staring down at the ground...