Hydra-Matic from the 1954 Chevrolet Truck Shop Manual Driving Instructions The Hydra-Matic has a neutral safety switch in engine compartment on the steering column... There are two purple wires that go to it...
The Hydra-Matic holds about 8 1/2 quarts of fluid... It has been recommended by
Gene at Restoration Hydramatics to use
Vavoline Detx/Merc ... Under the floor mat, if there one left, is a round plate towards the center of the floorboard, remove the plate and there is the dip stick... To check the fluid level the engine and transmission has to be at running temperature... I usually drive it to get the fluid circulating...
Looks like its in good condition from your pics... The
3100 emblem looks like the 54 style ... Check your
Vin # at the
VIN Buster to be sure of the manufacturing year...