looking at a 93 5sp touring with failed o-rings, but I also found a "Complete Cosmo 13B-RE Twin Turbo Motor" for sale on parts trader, I can have someone go check out and make sure it's good, as advertised, etc, but willl it swittch out since it isnt a 13b-REW?

 

It is not a direct drop in, it uses a crank angle sensor like the fc, the mounting is different. If you have enough money you can put anything in anything, but its not worth it. I would try finding a J-spec used motor or a rebuilt motor, but not from Mazda. They suck.

 

You need a long list of things... custom engine mounts, computer, ect. It is a great engine but nowhere near a drop in. If you want the fastest 2 rotor out there then the Cosmo engine should be you goal, but if you are not tring to break into 9 sec class leave it alone, alot of work.