for some time the 8 3/4 rear end has been the way to upgrade the somewhat fragile 7 1/4 axle... with the price of the Mopar rears following the BJ spiral, what are others using for additional strenghth? I have heard of 8.8 out of exploreres as well as Volvo rears... where exactally are the messurments of 51.400 being meassured from.. I hear Flange to flange ...drum to drum, asome 4even say backing plates? if it's drum to drum are they using the inside dimensions? how about flange to flange , should be easy but I have seen FOUR different specs on at least two vehicles 62-70 B bodys and late A bodys..But then you have those weird axles on early Bs.. At least every body seems to concurr on the spring pads...!

According to several sources:

1963-1972 A-bodies are:

7.25" axle 53.2 Flange to flange and 43.02 centerline of perch to perch

1973-1976 A-bodies are:
7.25" axle 51.40 F to F and 43.02 CL Perch to Perch
8.25" axle 51.4 and 43.02

1962-1970 8.75 "B body"
is 55" f to f and 44" CL perch to Perch

Hope that helps,

-D.Idiot

Im assuming you have an a body car so I gonna throw these options out there. One option Ive seen or have heard about is to use an 8" rear from a 70's maverick, The one from a granada or fairmount could pretty close Im guessing?? Another option is to look for a 73 or 74 duster with a 318 and grab the 8.25 rear from that to, for safe measure grab the driveshaft to so everything will match up. I believe the 8.25 driveshaft is a slight bit shorter IIRC- Pardon me but it's been a while since I've swapped rears But anyways the 8.25 a body rears are still cheap and the sure grips are reasonable to unlike the 8.75's which simply are to expensive to build and or change. Just my .02 here.

_________________
Barret-Jackson: Ruining the car hobby for everyone!

Actually you will be looking under all 1973-1976 A-bodies as some slant 6 cars came with the 8.25 also (mostly in /6 disc brake, 3spd floor shifted cars)...

You will have to watch the driveshaft from the donor car as A-bodies aren't all the same length between the front and rear wheels....


-D.Idiot