you can make anything work but the 258 is a pretty long engine the only way i see you doing it is streching it in the front and rear tube clip the front and a flat bed in the rear and then the tranny hump will have to be cut all to hell. i suggest getting a 1.6 16v efi and keep the tranny and put a lower gear set in the sammy t-case then
do a jeep eater yj spring conversion with your axles
but if you just want to build a little off road toy out of the stuff you already have laying around then fab fab fab
but i think with the engine tranny and t- case you have you will end up with a rear driveshaft around 6"long