Rear differential on 62' S-33

[meteorwingnut]

hey guys

i just picked up my new drive shaft..new tube, got rid of old tube with cracked rubber seals..new u joints..nice.

that said, now i am looking at what i think is the original rear end(no tag) and wondering whether i should have it looked at as its beyond my skill set by far!

---by reading the id tag inside door frame i think my car is a 3.25 ratio. for a ~275 hp 302 that i am building that seems okay as transmission has been rebuilt too.
-- my understanding is this is also an "open" differnetial instead of a locker. i live in a place with no snow and will not drive on dirt roads....do i need a locking or "partial" locking differential? should i get a new open one since i assume the rear on this car has never been touched. its an 8 inch..i did the wrench check.

--i figured i should have the bearing and seals done at the very least?

thanks for all your good answers!

[doberdawg]

If it is quiet, & no leaks, or small ones you can live with leave it untouched. 3.25 is a good gear ratio all around. Decent acceleration (no quarter mile racing)& decent gas mileage.

[eliot]

The 8" is the right rear end for the car and a 3.25 sounds right for stock. In my dads 62 (has a 5.0l efi motor with a t-5 behind it now), we were running a 3.73 open rear diff. If you plan on doing any racing, do not use an open diff with a manual. I broke the thing on the cars roughly 10th pass, sheered at minimum 4 teeth of the pinion gear, which was a 9 tooth. The car now has a 4.11 mini spool in it, which is nice for straight line use, but tight corners are not the most fun with it. I would say that for your car, the ideal would be a 3.55 or 3.73 rear gear posi unit, depending on what transmission you have!

[meteorwingnut]

thanks guys. right now still researching but considering a 3.5 posi-trak. we shall see. will keep you updated. Rebuilt 89' 302 and rebuilt C-4 going in the car in the next 2 weeks!