I bought this setup for my 65. It required 3inch U blots. I also upgraded to the larger UJ for the driveshaft.
I went for the disc conversion too (mine is a big bearing 9in) THe rear disc setup is a GM caliper. Only issue I ran into was they are a pain to bleed and I think a slightly larger bore master cylinder would provide much better pedal feel especially with power brakes.
If you have more questions let me know...you can PM me. overall build quality of the center section is great. I have a 3.70 gear, in a strange N case, billet Daytons support and yoke, with a detroit locker and 35 spline Moser axles.
1965 Fastback- 408w fully forged, GForce T5,9inch....and much more.
2003 Mach 1- Azure Blue, 5spd, IRS, Supercharged @ 10psi 480rwhp
1965 Coupe - SOLD