well the truck i have is getting to small for me! I've been looking at early 70's jeep pickup's. i figured the 10 means half ton and the 20 is 3/4 ton. but what about the j4000, what does that stand for? Did jeep do differant motor, trannny, transfercase combos like chevy did back then? if so whats the better of them? Or just point me in the right direction for the info online! thanks, a solid 10 points for most or best info or link