Dart 8 1/4 to D60 lots oh stuff to figure out

crackedback said
You better measure you 8.25 because I bet it's longer than 51.40. That's from that POS chart. I'll bet it's wrong. The rear from drum to drum is about 57 1/8"
You're best bet is to put the wheels and tires up under the car and measure exactly what length you need.
Did I send you a copy of the axle lengths program? If i did, use it! Fromthose numbers, it looks like you have it.

IMHO, TOTALLY disregard anything to do with the old rear axle measurements. It will do nothing but confuse you related to the desired goal. The only caveat to that, would be if you actually bolted the wheel/tire combo to the old rear and measured how far in they need to go.
BTW, if you leave the rear spring in the factory location you are limited as to how far you shorten the rear because the U-bolts will start to hit your housing ends. Looks like you have a factory 68-70 B body width 60.125, which shouldn't be an issue.

Actually your exactly correct (no surprise) I did measure and I found that flange to flange the 8 1/4 was the exact same length as the D60 flange to flange, give or take a half inch, I just trusted the official looking chart on moparts more than my wire i tied in knots at every interval then measured. and yes I did get the numbers from your spread sheet, (from crkd down) I was a little confused by a couple things.
8 3/4
Pass axle tube from C/L 27.46875 26.1875 2.5625 D60
Pass axle length 28.375 27.125

is this the difference between the two side if measured from the pinion center? I assume so but I didn't want to pretend to know.

if the axle is truly the same total length and I am moving the perches inboard do I really need to shorten the sides? Wont that bring the wheels closer to the inside? I don't really want that, they are already 5.5 bs and I have plenty of clearance to the fender. so the only real question is will the universal joint line up with the drive shaft if the dana is left uncut and the wheels are centered in the wells? If not how do I maintain the overall length and move the center section?

oh and the numbers were from sheet, it's a Dana 60 HD from 89 3/4 ton not sure of total length my notes are in my garage on the other side of town.