Bolt in a 401 in 84 cj7

the frame mounts are different but not the actual steel mounts on the block, if the cj5 came with a 258 then only the passenger side frame mount will need to be changed, but if it had a 4cyl bothe frame mounts need to be changed, Remember you will need a manual flywheel. A 176 behind a stock* 401 wont last one weekend if you a rough on the throttle, I would look for a t18 to dana 20 instead of the t176 to dana 300, the t18 will hold up, If you are looking for a t18 a t18 from a fullsize jeep will not work due to the longer input shaft, the bellhousings for the fullsizers were longer to accomodate the length of front and rear driveshafts, so if t18 is the way look to cj's from 74-79 they came with t18's if they were a 4spd manual, good luck and gooooooooooo 401!!!