OK, so you are looking for 5 on 4 3/4 (small chevy pattern) Many have used Camaro rears before. I don't know the years however. I would think with a 216 engine, you wouldn't want gears much higher than 3.55:1.
The width of the axle you use will also be determined by the wheels and tires you use. 61-62 inches wheel to wheel is a good starting point. You can figure that there is probably room for about 10.5 inches of tire under the fenders on each side. The bed is typically 50.5 inches wide + 11-12 inches per fender. Typically you will be looking at a width of 72-74 inches to try and stay inside of. Lets assume you are using 15 X 7 inch wheels with 4 inches of backspacing, and a tire that is 10 inches wide... 62 inch wide rear Minus 10 (this equals the tire width) minus 1 ( this number takes into consideration the offset of the rims equals 51 inches. In this example, you would only have 1/4 inch of clearence for the tires and the bed sides. Using an 8 inch rim with the same backsppacing will stretch the clearance to 3/4 of an inch per side in this example.
Anyway, there are many different schools of thought for rearends. Many different ones have been used. If you do a search, you might find the widths of some of the common rearends that have been used before. Or you can take a tape measure to the boneyard and measure away. Do your own math, and take your own measurememnts, and it should be pretty clear which rear you will need.
Last edited by bigbadswingdaddy; 12/23/2010 4:19 AM.