So you are saying that the switch is connected to the motor properly, moves the metal tang on the motor body and it still doesn't shut off? If so, you will have to remove the motor and have it gone over. To remove the motor you may need a clutch head screwdriver to remove the mounting screws as seen in this link. The transmission arms are held by a spring clip. The hard part is working around the instrument clusters/wires that obscure your vision and access.

http://s1116.photobucket.com/user/1...inkw_zpsn2v3yjrq.jpg.html?sort=3&o=0

If the motor needs rebuild and you don't want to mess with it yourself I recommend wiperman.com

Kent



1937 Chevy 1/2 ton
1942 Chevy 1/2 ton
1947 Diamond T Model 509
1951 Chevy 1/2 ton
1950 Chevy COE Model 5700 ~ "Barney" ~ And more pix