I had an '81 Mirada that came with 318/ 2bbl, and 2.76 rear. The spider gears went bad, and I replaced the axle with a 2.49 from a parts Cordoba. That was worse, so I finally found a 2.94 Sure Grip from a cop car, and bolted it in. I took an 1985 318 roller cam 2 bbl engine, and reworked it...