I wish I could tell you guys how it feels. I am waiting to get the exhaust put on, and I dont have the rear wheels and tires on ( getting those mounted friday) Ive played with it a little in the driveway with a single track and 14 inch wheels and tires. It felt real strong then obviuosly.
It should run well as I am thinking maybe get a 13.5 out of it like it is. Its a .030 over 429, stock everything other than intake which is a Edelbrock Performer. The exhaust should go on this weekend maybe and I should be driving it next week, i'll feel ya in on how strong it feels.
As far as the rear end. Junk the 7.5 thats in that car now, It will last about one good launch on some decent tires with the torque of the big blocks. I suggest you get a stock 8.8 out of a v8 stang. The 4 lug shouldnt hurt, there are guys running 9's on 4 lugs, I only swapped to 5 lug for more wheel choices and the parts were free
A 9 inch would be great, if you have one ive seen companies that make mounts that you weld to your 9inch that will make it fit in the fox body. You would also need to cut the axles tubes and order new axles then (as the 9 inch will be wider)
I would get a stock 8.8, rebuild the trac loc and maybe upgrade axles to a set of Moser's or Strange axles. I plan on it soon, I was jsut strapped for cash when I put the rear end together.