A 64 pack and frame can be set up with the 82 pattern rucksack waist belt and back pad too. The straps on the back pad need extensions though using 1" nylon webbing. Cheap and effective, but not necessarily comfortable for everyone.
Ojay7, to extend the backpad of the 82 get a few tri-glides and a little 1" webbing and you can extend them up that way. you may already have the webbing and tri-glides on old equipment not used any longer.