7.5 to 8.25 swap findings

As you can see I'm a really new poster, but thought others might be interested in the swap and what I came across.

Car the 7.5, 2.76 rear is coming out of is a '71 Dart Swinger, made and sold in California, slant 6, 904 auto.

I'm putting in an 8.25, 3.21 I found at the local self serve auto wrecker. Rear came out of a '75 Scamp. Has the large bolt pattern lug pattern that I wanted and of course the upgrade in strength for the later planned V8 swap.

Everything I'd read (not just here) said it was a straight bolt in job. I got the rear home, rebuilt the brakes with all new, pulled the cover and inspected the inside, changed the gear lube in it and cleaned it up and painted it.

I took the rear out of the '71 and that is where I noticed the first difference (yes, should have noticed long before, but there you go). The emergency brake cables are different. On the '71 the cable comes down the driver side and goes into a plate with a single bolt adjuster on it. Both of the rear cables hook into this and you adjust the tension with the single bolt. This means you have a short emergency brake cable off the driver side and a REALLY long one off the passenger side. On the 7.5 the passenger side cable was clipped to the rear end axle tube and then goes up and has a bolt clip that bolts to the floor of the car before it turns and connects to the adjuster.

On the Scamp the emergency brake system was different in that it had two shortish cables coming off the rear end one either side. These cables went straight forward on their respective sides and hooked into a C type clip on each side. In other words, the driver side had a C clip hook on that side and the passenger side had a C clip hook on that side. Each side of the car also had a tension adjuster that the other end of the C clip was hooked to by another cable.

So, and here is where I hope I can make this work, I had to remove my just built brakes (oh, 10" drums on the 8.25 by the way) and squeeze the clips in on the emergency brake cable from the inside to release them so that I could pull out the emergency brake cable from the backing plate. I also had to do the same thing on the 7.5 rear so I could get the cables out of that rear. I've now swapped the emergency brake cables over from the old rear to the new 8.25 one and have my fingers crossed that by doing so that I will be able to hook up the emergency brake cable system as it was on the '71 and get it to work.

For those that might be interested I'll post again to let you know how it works.

Also, a note on the rear brake hose or centre hose as it is called in parts books. Looks like the '71 and the '75 list different hoses. Appears the brass block at the end that bolts to the rear is the main difference although there could be a length difference, but I did not note what it was. For the correct hose for the rear it seems as though I remember that the length was somewhere around 14 to 15 inches from info from the parts books. The brass block on the end of the hose that bolts down to the axle tube has the brake lines to each side bolted to it. Looks like the lines come in at different angles between the two hose types. In my rush to pull the 8.25 I just cut the hose thinking I could bolt the other on that works great on the '71. Had been a long day by that time anyway.

So, I'm going to have a look today and see if the existing hose from the '71 can be bolted onto the axle and the brake lines from each side made to bolt in it. If not I'll be getting a hose to match.

On the plus side, I measured the cup area of the yoke from one side to the other of the yoke where the U joint from the drive shaft would bolt in. On both rears the yoke measured the same so I should be able to get the drive shaft shortened by 1.6 inches (thanks again for the answer to my previous post on how much to shorten the driveshaft by) and bolt it right in.

As they say, results may vary, but that is my experiences with a 7.5 to 8.25 swap so far. Hope it is of interest and that others doing the job may get a tip on what to check when sourcing the pieces. If I'd been more observant I'd have noticed from the start, but then when you are walking around the salvage yard and all of a sudden notice a new A body and it turns out it has the 8.25 your have been looking for ages for................. well you get a bit excited to say the least.

Cheers