69-70 vs 71-72 factory bench seat difference?

[John H.]

I was looking at a set of 69 GMC bench seat brackets 1/2 ton versus a 72 Chevy factory set (do not know if 1/2 ton or 3/4 ton). Is there a difference in the seat frame on a 69 vs 72? To be the same height installed, the seat frame has to be different to accomodate the taller brackets. The 69 seat had a rod to connect the passenger side to disengage to move the seat up or back and the 72 had a small cable.

Are there differences in 1/2 vs 3/4 ton?