Hey all Ive got a 1980 Olds Cutlass Supreme that I swapped a 1975 Olds 455 into and everyone says that im going to blow my rear up very soon. Ive been told to drop a ford 9" in there but was wondering if there was something I could do that was cheaper but reliable.
What rear end should I use?
- Thread starter Glen87
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If the 455 is stock a GM 12 bolt should be adequate and can be built up to be more than adequate. Ford 9" diffs place the pinion lower on the ring than the GM 12 bolt. While they may be slightly stronger overall they also require more energy to turn and therefore rob a little power to the wheels that you would not lose with a 12 bolt. Also a lower pinion also means a slightly greater angle on the U-joints. A 12 bolt should be slightly cheaper.
Is the motor stock?
If you're just driving it on the street, the 7.5 will be fine.
It's when you really start abusing it at the track with slicks that increases your chances of it letting go.
If you're just driving it on the street, the 7.5 will be fine.
It's when you really start abusing it at the track with slicks that increases your chances of it letting go.
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