In case someone was wondering if a e38 diff fits a miata it fits nicely. Pardon my rust.
https://cimg0.ibsrv.net/gimg/www.mia...6c2f9cc144.jpg
Jig that locates the axles where the miata axles would be was made to locate where to put the diff mounts. Diff input flange was made parallel with the trans output flange using a digital angle finder.
https://cimg6.ibsrv.net/gimg/www.mia...e7f276679a.jpg
Sleeves that the bmw diff bushings press into welded in.
https://cimg4.ibsrv.net/gimg/www.mia...d04f98e476.jpg
Front bushing bracket welded in.
https://cimg7.ibsrv.net/gimg/www.mia...f92d673757.jpg
Welded a single piece driveshaft from parts of a stock e38 two piece driveshaft.
https://cimg1.ibsrv.net/gimg/www.mia...5d06f1f1ac.jpg
Everything in place. Bmw axles used with machined e30 hubs to fit the miata wheel bearings.
https://cimg1.ibsrv.net/gimg/www.mia...1ea653cfb6.jpg
Driveshaft hoop just in case.

Amazing work.

These BMW 210mm diffs are tough as hell. People launch them HARD on the strip with 600tq+, no miata engine is going to grenade that sucker.

Thanks. This is the medium type 188 diff but still should be pretty strong.

I see!

Well, 188's are strong enough indeed