yep, just pulled out my 2 speed "powerglide" in my 68 firebird and put in a turbo400 and realised I had the ST300 2 speed all along... only problem now is I have 3 forward gears but only 2 on the console - I presume one can get the correct Drive, Second and Low console part and just pop out the old 2 speed part and push in the 3 speed part
