Ok guys. This is my first posting to the forum and I thought it was about time to get my feet wet. I've been readin' this forum for a couple of years now, an it's been a wealth of info.
I own a 1954 Chevy 3100 pick'em up with a 4 speed Hydro-Matic tranny. The truck has been kept up well and is bone stock. Yup, they made the 4 speed Hydro-Matic for the Chevy's starting in 1954 and there are some differences between them and their manual transmission cousins. For instance, the cab has no provision for a hole for a clutch pedal in the floor (makes sence), the shifting pattern goes like this: N 1-4 1-3 1-2 R, and there is no floor starter button 'cause the ignition switch has the starter switch incorporated. There's also an extra hole in the floor over the tranny to access the automatic transmission fluid. As far as how rare these trucks are, I have no information that's verifiable, but they are considered pretty rare.