It should be fairly obvious that an AMC V8 swap will be easier into an AMC Jeep than a Chevy V8 would be. Turning the big tires is more about your axle gearing than the engine. I'm assuming you're planning some 1-ton axles if you don't already have them and something beefier than a T-5...
'86 CJ-7 Laredo: 4.2,T-999,D300,D30/D44,'94 YJ tub, full cage, Shrockworks rockers, OYR corners, AC,cruise,restored seats,3 tops,2.5" Superlift,F-T shackle reversal, RS9000x's,35" Dunlop Mud Rovers.
'83 Scrambler: time & money pit under construction with parts from CJ's,YJ's,TJ's,FSJ's,GM,Ford,IH,Honda,Toyota and a whole lotta aftermarket & custom stuff.