Ray, about the only thing I see that you need to be aware of is the fact that the '75 front and rear are a little bit wider than those on the '64, but that can be made up with wheel offset. I cut the brackets off the '75 with a portaband, and I washed the brackets off the '64 with a torch. I can weld, but I opted to go with the TIG because it uses less heat. I didn't want to warp the housing.
Sorry for post jacking, Arctic......I don't know about the 3/4 ton stuff mating to 1/2 ton stuff.......I do know you can put the spindles on if you change the ball joints, but I wouldn't. If you just change out the spindles, you will have to pull all of your shims out of the uppers because the lowers are mounted differently from drum to disc; the lowers are closer together on the newer model. When I asked about the swap, I had someone post their experience with just swapping out spindles. I also know someone who just swapped spindles on a '65, and he had to pull all the shims out of the upper to even get it close to alignment; it's still out, but he can live with it. I can't.
Yes, Ray, Mark spanked 'em......I hope he does the same in the 600.
BTW, I got the frame blasted & painted....I just got my new machine @home, and I just loaded FrontPage on it last nite. I'll be updating the website this weekend.