They had a different number, J200/3000/4000, the J10 came out in 1971. The pickup body style is the same from 1963 to 1988, they change grille, interior, fenders etc... The Wagoneer body also is the same, from 1963 to 1991, except grille, interiors etc...
If you are going to build a stock Gladiator, early model, you can build it with independent front suspension, instead of a solid axle.