I've got a chance to pick up a full 9" rear end for a hundred bucks, however the guy only knows that it's out of a Mach 1 and he doesn't know the year. He says the backing plate to backing plate measurement is about 54". Anyone know how that measurement would correlate to year? Can you use a '71-73 rear-end in a '69? Thanks.

 

http://www.maliburacing.com/ford_9_i..._nine_inch.htm

http://www.kevinstang.com/Ninecase.htm

 

It's 69/70 measurements (54.25). And that also means that you're getting a deal because Machs came with Posis

71/73 is 56.25. Perfect, if you're gonna run late model wheels
It will fit on a 69, it'll be wider. That's all.

 

Thanks for the help guys, that's exactly what I was looking for. I'll report back after I pick it up.

 

Actually Fords came with Limited Slip/Traction Slip.

GM's came with Posi-Traction.

 

LS was not standard on Mach1s...