[22GT]

Neither. Sell the 4-bolt rear to someone who needs it, and buy a V8 rear. It is possible to attach the V8 to the 4-bolt rear, but it'll only take one or two burnouts to blow that little 7" rear to bits.

Just so you know, the 66 2.77 driveshaft was a little thing, while the C4 driveshaft was much larger, like the V8, but too long for a V8 rear.