Need help identifying r&p set

[BenL]

I recently acquired a rebuilt diff for my 86 and have no idea what the r&p ratio is. Normally the stamp on the ring gear provides some kind of info. I’ve googled searched and searched here as well as other forums but can’t get a conclusive answer. My assumption is it’s a 4.88 only because there is a T488 number. Here is a picture of then stamping any ideas?

[fika84]

All you need to do is count the teeth and divide.

Number of ring gear teeth / number of pinion gear teeth.

[Grady]

Originally Posted by fika84

All you need to do is count the teeth and divide.

Number of ring gear teeth / number of pinion gear teeth.

What? Do math? That is crazy talk!

[BenL]

I know that much. Figured I’d ask being as diff/r&p swaps are common with these cars and someone may have simply noted the part numbers they used. If it is a 4.88 and the part number I found from summit racing is correct this gear seat is really really cheap. I don’t have any money in this diff so I may have found another more affordable alternative for everyone.