I'm currently working on the engineering for the restomod of my 69 Wagoneer. I am planning on running the 4.5L Cummins ISB engine( 4 clyinder version of the Ram truck 6 cylinder engine) and an Allison 1000 transmission. Would the Dana 20 case be stout enough to handle 400 pound feet of torque or would I be better off with a Dana 300? Also I'm planing on using Dynatrac axles a full floating Dana 60 in the rear with a Dana 44 in front. I have a question regarding which springs to use. I'm anticipating a 35-36" tire with the later 6" lift if possible seeing that the axle housings can have the spring pads anywhere on the axle as needed, what are the specs for the wide track axles regarding spring pad location? I am planning on the "wide track" flares and fenders to make it look finished. I have most of the bugs worked out including the PTO driven hydraulic system for the milemarker winch. The build would be done in steps with the axles and suspension coming first then the "power package". Yes it will cost a bit but seeing a new truck costing close to 50K if I am able to get this done for 30K I think it would be a good investment.