Hey just introducing myself since Im a newbie and all.
I am checking into this site not because I want to V8 swap my miata but because I want to learn about how to swap in a 7.5" Ford rear end in a soon to be turbo miata. It just so happens that my miata's diff just exploded yesterday and I have read about this being a common occurance. And these miata torsen diffs ain't cheap. So after talking to someone locally they mentioned this forum and the idea of 7.5" diff to me. Now I am here and ready to soak up some information and try and save some money and time in the long run,
Thanks Scott

1991 miata 1.6, Wentzville MO

 

You can get all that you need to mount the 7.5 (hanger, axles, hubs, etc.) from Monster Miata (www.monstermiata.com) for about $1000. The rear itself and the half shafts (needed for the CV's) you can get from a yard for under $100. I've seen them in both 3.27 and 4.10 ratios with factory limited slip. Doing this means eliminating your PPF, which is much less of a big deal than most Miata people will let on. If you do eliminate the PPF you're going to need a way to secure the rear of your Miata trans. I believe V8Roadsters sells a crossmember that bolts in. I'm not sure of the price though. You'll also need a custom driveshaft which I may be able to help you with.

Good luck,
-Jason