henryk8398

I haven't determined the rear end ratio of my 98 yet, but I'm pondering putting different gears. Seems like a 92-96 caprice/impala rear is a pretty logical choice and economical to boot. While the mounting points may be the same, other questions came to mind:

1. If the rear I find comes with disc brakes, will I need to get the proportioning valve from the donor car? Anything else I might need?
2. If the rear comes with drums, will the later brake lines have the same threads?
3. Will the later model yoke work with my driveshaft. Are the yokes easily swapped?
4. Any other considerations for a rear end swap?

From all my research, it seems like lower gears is a great way to wake up these 307-powered rigs and certainly won't hurt when a larger motor finds it's way under the hood in the future!

Any thoughts would be greatly appreciated!

J-(Chicago)

You will need a 1" shorter driveshaft if the rearend is an 8.5, and the wheels are 5 x 5 bolt pattern and not 5 x 4.75.
I have never had a rear disc brake car so I'm not sure on the prop. valve question.
Don't forget the ebrake too, another issue.
Replacing the rear brake lines is easy, I would worry about everything else first.

The thing to keep in mind is: These cars are dogs. No matter how much you polish, a turd is a turd.

I'd enjoy it as is, or swap the whole drivetrain out at once in one fell swoop of an upgrade for more horsepower. A thicker gear may give you a little more pep, but not enough to justify a rearend and driveshaft cost in my opinion.

henryk8398

Great point, but from a finance standpoint, it will be easier to do one part of the drivetrain at a time. That also lets me know the improvement in performance each upgrade provides. The original 307 has lots of life left in it. That's a good or bad thing, depending on your viewpoint.

Eventual plans are to drop in a SBO 350 or 403, but that's pretty far off for now.