Transmission and rear end combo

First your gonna have a heck of a time fitting a A518 in an early A-body if that's what it is. A500 maybe with some cutting and welding. A518=tons of cutting and welding/enlarging the transmission tunnel. Secondly the Dakota 8-1/4 is a whole bunch wider than your cars 8-1/4 and I don't think parts will interchange cause they changed the axle spline count somewhere through the yrs. between them.