A727 Rebuild kits redux - Rebuild kits everywhere (62-70 vs 71+)

i'm going to get into a couple of early cable shifter 62-65 727's , i'm changing up the front pumps and conv's to the 66 up type . but in my read through your thread i think i read that the 71 up pump can be used with the same front drum set up . is that true , everything in the front swaps out or what ?