30th Nov 2012, 16:17
"because before about 1982, they only had three-speed automatics"
Wrong. There was a four-speed Hydramatic available in the "senior" Oldsmobiles and Pontiacs, and possibly some Cadillac models, from the late '50s until the early '60s. I once owned a '64 Bonneville that had a four speed automatic.
30th Nov 2012, 15:56
That 58 year old Pontiac had a 4 speed Hydramatic as original equipment. It was GM's first multispeed auto trans, first available for the 1940 model year, & was continued into the 1960s when it was replaced by the 3 speed Turbo Hydramatic 400 & 350.