i would suggest you go with a 251 dodge truck engine. that's the long block, factory bore, with forged crank. the military used tons of 'em up through about '69, so there's gobs available. they will look correct and should give you the best performance and endurance, IF what i've been reading is correct. for more information, go to
www.vintagepowerwagons.com, and they'll even talk to you on the phone toll free.
good luck!
