Not that there is anything wrong with swapping to a 465, but functionally you gain next to nothing, same direct drive in high gear but the 465 should be the better choice if you have both to choose from.
Check out this tech tip for pinion angles and such, mostly the links in it:
http://www.stovebolt.com/techtips/driveline_setup.htmlThe perches should be about the same width as the springs, defiantly not wider, as the U-bolts would then not be snug to the sides of the springs, and not much narrower, as you want a good seat/contact area for the springs.
Best to assemble the truck with the perches loose on the axle housing, but layout some center lines so you get them positioned correctly left to right. Then with the truck on a level floor check and correct the angle of the pinion as instructed in the manuals in the link above, then tack weld the perches to the axle, remove and finish welding, or if you can do a good job of welding them all assembled go for it.
If you have a pickup you may have a problem finding wheels to fit inside the fenders when you use the Dana 70. I had wheels made for my 52 1 ton with a Dana 70HD. I also moved the spring perches to correct the center to center distance, but I kept the same angle as the Dana already had. Then later found I had to make 6.5 degree correction shims. So, learn from my mistake and assemble it all before you set the pinion angle.
Grigg
