1) does the 457 u joint fit the factory Ford flange yoke or do you have to change it? Fits
2) does this require modification of the factory a body driveshaft? Yes. Needs to be shortened about an inch.
3) what shock mounts are you using? Cheapest I could find for an 8 and 3/4
4) what spring perches? Will any 3 inch perch work? Pretty much.
5) where did you find that pipe cutter? I looked on Ebay and they arent cheap the cheapest no 3 I have found is around 100 bucks. Pay the shipping and you can borrow mine. Only been used once.
6) when you welded your spring perches on what angle was the pinion at? This is a major concern for me. I already forgot, lol. I think it was down a degree or two?