That is like the ford versus chevy question, everyone has their opinion and favorite. You could spend a fortune on axles to get the BEST. The dana 30/20 axles were used behind all the AMC v8,s. I have run all of my jeeps with v8s on those axles and 33,s and not had any problem except replacing front ujoints from time to time after doing some tougher trails. wagoneer dana 44,s would be better. As for the trany, are you wanting a auto or stick? The t18, t150, t176 jeep manual tranies will hold up to the v8, but you will probably need a adapter for the engine no matter what so you could really put any trany in there you wanted. You should have the dana 300 tcase and only the t176 of the three I listed will bolt directly to the 300 with out an adapter. the t150 would be the weaker of the three. I am running a muncie car 4spd so your options and endless with adapters.