Being it's a Mirada it will already have the low gear 904 trans in it. There wasn't much that could be ordered different mechanically than what you have, but Diplomat cop car parts will bolt right in. Go find a Diplomat fleet car, fender tage code A38 (pre 1983), or AHB (1984 on up). They all came with 8.25" rear axles and could be ordered with up to 2.94 gears and Sure Grip. Grab the rear springs, and both the front and rear sway bars while you're at it. Your driveshaft will probably have to shortened.