The best willys message board is at:
. You have to sign up to view messages and post. It is occupied by people who have both stock and repowered willys (I am one of the repowered ones). If you are hacking up an otherwise perfectly good truck then you will get some grief for it but if it has already been hacked then you will be ok. You may find that the 4.0 is too long for the engine compartment and you may want to consider a 4.3L Chevy V6 or SBC or Ford V8 (better cause the dist is in front). Parts and adaptors are easiest to come by for the chevy and ford engines.
1955 Willys CJ5 Buick 225 V6 160HP 270ft-lbs, T90 trans, Warn OD, PTO winch, Spicer 18 T Case, RS9000's, Dana 25F/ 44R,
5.38:1 gears, 11" brakes, Bestop Supertop, Hurculiner