Just a thought, if the mazda bearings are a little bigger, why not just machine out the toyota hub to fit the mazda bearings. it would keep a greater strength integrity to the spindle. You can also go to the Timken web site and if you go under the products section and select catalogs, it gives you bearing applications for almost every part of any car or truck. they also have a bearing spec catalog that would give you the dimensions of the bearings. and also if you go to the autozone website, you can look up brake rotors under specific vehicles and they have the dimensions of the rotors on the pictures. About a month ago,i put a set of 20's on a 76 Widebody Porshe that had a Mercedes bolt pattern. I got adapters for the rear, but put redrilled 68 mustang hubs on the front with mercedes rotors so everything would fit. Anything can be done, just gotta do your homework. Give me a shout if you have any question 484-797-6637