I don't have the widths, but once you get past '00, the axles get rather wide, even the '88-'00 axles might be a bit on the wide side, especially with the 4x4 version. 2wd should be ok, though. Also, the basic axle is the same from '73-'00 on 2wd, so that might be the best option. If you wan the rear disks, the later axles brakes should be a bolt on, I'm esonably certain the mounting flage is the same. Or it could be easily modified to fit. You would need to scavenge the appropriate brackets froma disk brake truck, though.
On the 402, it is essentially a bored out 396, stroke is the same. So yes, the 396 and 427 heads will work. Torque output should be fairly decent, perhaps a bit more than a 396. Cam selection would have more to do with that, though.
