Manual window regulator question

[LeesTruk]

When I bought my truck, a 1980 C10, I occasionally would pull off the window crank handle. No big deal, I'd take care of it when I rebuild the vent windows. So I take the doors apart, do the vent windows, and I figure since I'm in the doors, why not clean and re-lube the regulators too. Did that, replaced the window runs, reassembled the door, slid on the crank handle (no clips yet), everything works nice. So I had gotten some new crank handles, tried them on the regulator shaft and then found out why the crank handle would pull off. The splined shaft is longer than the handle is deep! Anyone know when the regulators changed? I'm wondering if I have later model regulators on my truck . I don't have a problem, per se', just want to get crank handles that will work, and not pull off when operating the window. Thanks