The stock Wagoneer suspension does not need any modification. With decent shocks and original leaf springs both ride quality and handling should be comparable to an 80 series. This rig would need some body work and mechanicals would need to be checked. Axles seem to have been Toyotafied already and probably a diesel engine in there which needs to be replaced. The rear body chop seems rather well executed and front is in good shape. If original leaf springs are not available some Toyota replacements will also work well. All in all its a question of budget and some hard work, but in my opinion you'd be hard pressed to find a better 4x4 platform to sink all of that into.