I have '69 Buick Skylark 2 Dr. Hdtop Coupe w/350 Motor What would have been the transmission model that came with this car. It is supposed to be all original.
Automatic would probably have been ST300 two speed. (Think 70 was the first year for the TH350 in the smaller cars.)
69 was the first year for th350 tranny, so only 2 auto trannies available in 69 were the 350 and 400 (GS400). 68 was the last year for the st300.