The Grand Wagoneer of that year used a Chrysler-built TorqueFlite automatic transmission (likely a TF727 or a TF904 depending on the engine and options). The 700R4 is a GM transmission with a completely different bolt pattern, input shaft, and overall dimensions. Adapting it would require major fabrication, custom driveshafts, and potentially modifications to the transmission tunnel. The cost and complexity would far outweigh the benefits.