6v solenoid starters were used in hydra-matic equipped 1953 GMCs and in hydra-matic equipped 1954 Chevrolet trucks. 6v solenoid starters were also used in double-duty and maybe COE trucks as early as 1948.

http://chevy.oldcarmanualproject.com/1929_57chevyparts/57cmpc0201.htm

The 6v hydra-matic starters had different drive-end housings, so they might not be a straight bolt-on with manual transmission flywheels - maybe someone will post information about this?

Tim