Mike, GM only used two sizes of gears. The P/G and std trans used one series then went from 17T upto 24T and the older TH400 and newer 700R4 used gears with teeth from 37T upto 44T. I have some of the smaller ones if I can help you out. Do you need it before the Jack Halton Run ?

Ontario Inliners
1965 Chevelle
1940 Chev
1965 Chev Pick-up
1970 MGB Roadster