Hello I to am building a 1975 cj5 and at first it was this that led into doing that wich ends into its all torn apart and slowly getting put back together with more newer parts but what ive learned between the changes from pre 75 to later 76 .A motor is a motor 258 304 360 A axle is the same dana 30 narrow trax dana 44 narrow trax they ran them for a while pretty much everything else has its diffrences they extended the lenght in the 76 s which means drivelines leaf springs anything protruding the firewall ie clutch linkage and steering columns is diffrent lengths mine doesnt have a bomb i mean gas tank under the pilots seat its tucked in under the back end although theres a built in tool box under the copilots side thus making passenger seats harder to modify to fit .Lets see what else no thats about it motor and axles are about the few things thatll bolt in anything else requires a cutting torch ,grinder,drill,welder creativity you get the point
Bye the way finding a full front dana 30 even out of cj7 (narrow trax of course) with disc brakes is a good mod up to 79 i belive all had drums but 80 -83 had disc brakes (i think)
Have fun with it