Big Block Conversion $$$

really a c-body with an 8 3/4 is the best donor. they usually have 11" drums out back, certain years the axles are long enough to send them to moser and have them resplined. have the housing narrowed with new perches and you have an a-body big bolt pattern 8 3/4 for dirt cheap.you have the motor, trans and a driveshaft you might be able to have shortened. really are better off going with a big yoke o nthe rear and having a 3 or 3.5" driveshaft made and balanced it will last forever no matter how you beat it.