question about a c30 front k member change out

[Budman56]

I have a 63 1 ton that I would like to change out the front k member to disk brakes so I need to know is a 3/4 ton front k member the same as a 1 ton? I have located and purchased a 1 ton 1990 dually rear end so now I have a buddy that has a 3/4 front k member and he says it the same but I dont know. by the way I want to keep the same rims so the front end will need to work with these rims.