They will fit but not without mods. And J10 axles aren't 3/4 ton, they're 1/2 ton. Nearly a foot wider, rear perches must be moved in, front springs must be outboarded. front needs to be from a 74 to 79. The back can't come from a quadratrac truck.
77 CJ-7- AMC 360, Edelbrock cam, MC2100, Fenderwells, CJ T18/D20, Chevy D44/EB 9" rear, Trutrac f/r, 4.11, SOA, 1.25 lift shackles, 35x12.50 BFG KM2s, Shackle Reversal