Belvedere rear ends

[oliver]

Put my new 66 belvy with a slant and 3 speed manual on the lift and noticed that i came with a 7.25" rear axle I thought the smallest rear end available on them were the 8.25"... i also noticed that in this chart



the 7.25 was never available.... i was going to just regear when i swap in my small block but now it seems like i have to do a rear end swap. If i end up finding a 8 3/4 i did notice the width between the spring perches are different, how did they mount the springs closer together? Should i keep the stock width and reweld, or change the mounting on the car? Thanks!

[Meep-Meep]

I don't know if that chart is completely accurate. I could be mistaken, but I had a 68 Belvedere slant 6 3 spd with a 7.25 rear end.

One way to change the spring width is to use offset shackles and modified front hanger. Also the chart says the 8.25" B body and the 8.75" 62-70 B body has a different spring CL width. I don't recall having that issue.

[RGAZ]

Originally Posted by Meep-Meep

I don't know if that chart is completely accurate. I could be mistaken, but I had a 68 Belvedere slant 6 3 spd with a 7.25 rear end.

One way to change the spring width is to use offset shackles and modified front hanger. Also the chart says the 8.25" B body and the 8.75" 62-70 B body has a different spring CL width. I don't recall having that issue.

My 69 came with a 8.25 and I swapped a 8.75 with no problems. Width matched perfect.

Randy

[70WM21 W1 V6B]

I too saw a lot of 7.25's in B Bodies and they do NOT take any kind of abuse.

As for the 8-3/4 difference I think when you get the 8-3/4 you also got a heavier duty leaf spring (wider also) which if swapped as an assy springs and axle it would bolt right in with the difference being leaf spring width which when split between the 2 would be 1/2" per side centerline pivot. I do not think the factory tooled up different uni bodies for 7.25 rear axles, only the hanger brackets, springs and shackles and shock plates and axle.

If your gonna swap out the rear axle go with the 8-3/4 for sure, there should still be plenty of housings floating around.

[oliver]

What do you think would be required to swap in a 8 3/4 into the car? The front mount and shackle mounts are in different locations than 8 3/4 cars. How do they differ?

[Manifold]

Yeah, that chart isn't complete.

Take a few measurements, the important one being the spring perch width. For your car, it should be 44". If there's nothing odd going on with your car, then it should be just a matter of pulling the 7.25 and installing the appropriate 8.75 rear. I'd say stick with a 64-67 B-body rear (earlier than that had the 2 piece axles IIRC), but you would likely be OK with a 68-70 B-body rear - my notes say the 68-70s were slightly wider (like 5/8" overall WMS to WMS). Both of those have the spring perches set at 44" apart.

Be sure to get an accurate measure on any rear you buy! I picked up an E-body 8.75 for my 68 B-body (the E-body rear is 1.5" wider than a '68 B-body rear) which supposedly had the perches relocated for a B-body. My quick measurement wasn't good enough - turns out the perches were set 1/2" narrower than a A-body rear. So, off they came and I welded on new perches at the right width which also allowed me to set the pinion angle just right for my car. Worked out in the end... but meant more work than I had anticipated.

[rrunner]

Originally Posted by Meep-Meep

I don't know if that chart is completely accurate. I could be mistaken, but I had a 68 Belvedere slant 6 3 spd with a 7.25 rear end.

One way to change the spring width is to use offset shackles and modified front hanger. Also the chart says the 8.25" B body and the 8.75" 62-70 B body has a different spring CL width. I don't recall having that issue.

I don't think, I know it's not. 65-67 8 3/4's are't the same as 68-70, they aren't as wide. That chart shows 68-70 spec's. I also thought the 8 1/4 came along in 69.

[Manifold]

Originally Posted by rrunner

I also thought the 8 1/4 came along in 69.

It did. I just pulled a 69/70 8 1/4 out of my 68. Ran the casting number to see what it was. It isn't listed on that chart.

[dcatcha]

Here is the complete 1966 Shop Manual for the car, and it is FREE!!

http://www.mymopar.com/index.php?pid=109

good luck!