or I could just buy the right gears for the trans and not have to worry about ratios and it is primarily an offroad toy but I can still run it on the streets if I want to

 

I jumped it up to 30x9.50/ 15'sand it still has loads of power, gets better mileage, and is only 1.6 mph off on the speedo. As long as I make sure one front wheel will slip when it's in 4x4, I shouldn't have any trouble. I have a 69 chevy one ton with the same issue's and that works fine on it.

 

After some more study, Mazda compensated for a gear ratio issue by sending the '87 model i have out with 235/70/15's on the rear and 215/70/15's on the front (manufactures label on the drivers side door post). I am trying to easily correct the speedometer error for now, I figure on installing a shorter tire on the front to compensate for the gear ratio difference after I get the speedo corrected. I am still working out a few bugs in thye system, but have achieved a pretty good driveable setup today.