Sorry man to vague, I want to put an 8 1/4 and wanted to know what may be close to the same length of my 7 1/4. That way I won't have to chop too much. Moving the spring plates is no prob, but I dont want to mess with tube or axle lengths.
Here is some info:
1963-1972-7.25 axle in A-body: 53.200" flange to flange/43.02" leaf
spring or spring perch center-line to center-line/10.09" axle center-line to yoke centerline. These are 4"on 5, or "small" bolt pattern.
1973-1976-8.25 axle in A-body: 51.400" (same as A-body 8.75 housings) flange to flange/43.02" leaf spring or spring perch center-line to center-line/11.69" axle center-line to yoke centerline. These are 4.5"on 5, or "large" bolt pattern.
As you can see, the perch-to-perch measurement allows the 8.25 unit to bolt right into your car, and the flange-to-flange gives even greater tire clearance. Driveline must be shortened. One lives in my '65 Dart just fine. However,the 8 1/4 housing was only a large bolt pattern unit, according to the book that I have; So, since your car is a 1st gen A-body, small bolt pattern car, you will to use custom axles, like YUKON's, to retain your small pattern, or move up to the large pattern. I run '73-'76 A-body discs, so it's not an issue for me.
