I just swapped in a 304 into my 84 CJ7 in place of the 258. A couple of things you will need will be specific V8 motor mounts and buy a flexplate for a V8. I believe you can use the same plate for both the 304 and 360. 258,s are neutral balanced and the AMC V8,s are externally balanced by the flexplate. Also the V8,s generate more heat so you might want to get a 3 core or better rad.

84 CJ7 304 HEI 35 BFG,s rear dana 60 with detroit locker,Viar compressor, fibreglass body, 2 1/2 spring lift, TF999auto, Warn 8000 winch, Plus a cool little trailer on 35,s. JEEP stands for just empty every pocket