For anyone looking for a cheap 3.63 gear set from the early 626's. Posting this separately for those not looking at the 3.3 R&P thread.

Here's a quick list of junkyards currently claiming to have the old rwd 626 rear ends available. Ignore the pricing shown, call them. It's likely cheaper going direct than what's on the car-part website. Ignore the title of the link, it's really is for 3.63 gears.

https://www.miataturbo.net/forum/t38717/#post449308