1st off Yes, I`ve search and read the to post about 8" rear but couldn`t find a straight answer.
I have a 74 wagon with a 6 3/4" and I picked up a mustang II 8"(year unknown). I know I`ll need a shorter driveshaft and the 6 3/4" brakes MAY fit..I won`t know until I measure the backing plate hole.
Are the U-bolts,shock plates and other mounting hardware the same between the wagons 6 3/4" and the mustang II 8"?
To answer a few of your questions:
1. NO, the 6-3/4" drums won't fit the center hub on the 8". The 6-3/4" hole is too small. I think there were a few minor internal brake hardware parts that seemed different. That said I recall mixing and matching for the best of my combined parts. You have to use the Pinto E-brake cable as the mount location on the Mustang II is not in the same place.
2. The Mustang II had different lower shock mounts. So in that regard they won't work. When I bought my 8" I got EVERYTHING with it. However, I found the bolts and other associate clamping pieces were the same. At the time of my purchase there was some information about the rubber cushions being different, but I did not find that to be the case.
3. Lastly, my Wagon was a 1973, 2000, 6-3/4", with a C-4 Auto. I installed a 2.3 with a T-5 and added the 8" rearend. I did NOT have to change the drive shaft! It fit perfectly (I believe it was 45-1/2"). I can't account for any other configurations. I hope this helps. In the case of a rearend swap get a "drum to drum" if you can. When I bought mine it was only $10 more. The price was $116 out the door at Pick A Part. That was at their "regular" price. At their 50% off sales it would have been about $70-$75. But, it took me 6 months to find one that didn't have pumpkin pilaged so I snagged it while I could.
Tom
As an addendum to what I just posted above:
1. The Mustang II shocks, does anyone know if they will work with the Mustang II lower plates? Given the rarity of the early Wagon shocks it might be a work around. And depending on the plates there is the possibility of mounting the sway bar too - with some fabrication.
2. As it regards the shock, I used standard shocks on my Wagon. They are actually about 1-1/2" too short. On the top I use a number of the shock bushing washers to effectively add to the length of the fully extended shock. On the bottom I used a tubular spacer for the same purpose. I will admit it took some effort to get the threads started with all these sapcers. This effectively made the shock about an 1" longer that it really is. Thus far the missing 1/2" hasn't seemed to make a difference. Oh, and consider this at your own risk.
I`ve read here that the 6 3/4" brakes will work on some 8" rear ends.. I depends on what bearing size used on the 8". I`ll find out when I pull mine apart.
I also rephrase my question. Will the shock plates from the 6 3/4" work on the 8"...
Quote from: wedge446 on November 16, 2008, 07:59:26 PM
.....Will the shock plates from the 6 3/4" work on the 8"...
Yes, as long as the 8" you are talking about is one that was made for a Pinto/Bobcat/Mustang II.
Bill
Yes, (also), I reused my 6-3/4" shock plates with the 8" rear end.
I can't speak to the bearings and the 6-3/4" brakes on the the 8". My 1973, 6-3/4" drums had too small a hole for my 1978, 8" rear end.
Tom
Thanks for the info.
The shock plates, rubber pads, and the 'upper plates' are made to fit each other as an assembly, and to fit the springs and shocks they are made for.
The early cars have smaller 'hub' sizes. I have seen where people post that when they swap to a different rear that different wheels and or drums are needed, but that might only be with the early cars.
Bill