6 cylinders- 232,258, Jeep 4.0
8 cylinders- gen3 amc v-8's, 304/360/390/401
To the best of my knowledge all gen2's also share the same bell housing but the short deck blocks are not a desirable due to the limited displacement.
Also AMC motors are externally balanced so you will need a flex plate to match the respective motor size.
Obviously I didn't bring up all the supporting mods. Suspension/cooling/and drivetrain necessary for the power increase.
1979 CJ5 408 AMC dana 60/14b, T18, d300, PSC hydro assist
1948 Willys CJ2a LS 4.8/sm465 scout 44's