Do we have a 12 tooth gear?

[Skunksmash]

Do we have a 12 tooth gear on the power window motors on these old trucks? Mine in particular is 87 model. Ever since I've had the truck its had a slow passenger side window, and tonight I checked the regulator pretty thoroughly and there I can't find a problem there. Most of the time its the motor anyway. I want to use AcDeclo brand, the good stuff.

I'm trying to find the right AcDelco part number. I found 4 different part numbers on Rockauto, but I like to cross check everything just to be sure. So I checked the "Will this fit my vehicle" on both ebay and Amazon, and both of them say it won't. Ebay even gives long lists of all the makes and models that the parts will fit, and R10 and C10 are never on any of those lists. I have a feeling it would probably work if I just ordered it from Rockauto, but my neighbor recently went to Oreillys for his F-150 and they gave him the right part, sort of. Its the right motor, but with the wrong number of gear teeth.

So he had to go back and get the right one, and it finally worked. I really don't want that to happen to me, since I'll be ordering online. Looks like Autozone and Oreilly's don't sell AcDelco brand window motors for these trucks. So can anyone help me confirm? I posted a pic of the one that Rockauto shows for my truck, note that it has a 12 tooth gear.