I am searching to find information about these diffs. I may use one in my Nostalgia dragster because I have read that there is a range of centres avilable.
But I cannot find any clear information about the ratios available and what vehicles had these diffs.
Also, who may sell aftermarket items, Thanks

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John Daley
Nostalgia Dragster

The 8.75 rear is an excellent axle, I think its better than the Ford 9 inch. The where used in 340 powered A bodys, in B bodys (mine has one, even with a slant) mostly in 383/400 cars and 440 and 426 cars with automatic's. They where also used in C bodys, again with the big block engines. The had ratio's of 2.76, 2.94, 3.23, 3.55, 3.91 and 4.10. Open or sure grip. They have no C clips to fail. Randys Ring and Pinion is an excellent source for parts and service, as well as other ratios. These axles can be cut down to fit under any car. They are getting expencive to get though: if you can find an A body unit they are almost worth there wight in gold. They also have the small bolt pattern and odd ball drum size. If you don't like the tapered bearings with the adjuster, you can install green bearings that eleminate the adjuster, but you'll have to make due with ball bearings. GM used them on their axles and worked fine, but the tapered are better for side loads. There is a guy on Moparts.com called DrDiff that also deals in 8 3/4 parts.

Here is Doctor Differential's website, I just ordered axles, bearings, and seals from him...best prices I could find:

http://members.aol.com/doctordiff/index.html

They were used in trucks up to the 1974 model year in N.America... disregard the model out of pre-1965 vehicles as the axle is attached to the brake drum with a large castle nut, and is not really compatible with later vehicles (but the '741' center section can be transplanted to your axle)... Stock ratios are as Eric says, but here in Oregon the Forestry Service bought a fleet of 1963-1964 Dodge Trucks with the 225 slant six 11" clutch and 4.56 open 8 3/4" rear diffs, so in heavy duty 'haulin' vehicles you may find the 'drag gears'...

the Ford 9" is comparible, but Ford made the axle housings in 4 different 'flavors' and only the truck and 'battleship' car (Lincoln) configurations had nice durable housings... to shave weight out of it the Mustang 9" was too light and has durability 'issues', side by side in an abusive test like a demo derby both the 8 3/4" and 9" will take all the abuse they can and still keep going...

-D.Idiot