DADS50, the switch with light is a good idea. Do you Know the brand/source/part-number.
People have posted information about a back-up switch on an SM420 4-speed transmission, but unless you gave the right years the case has to be drilled (and the switch has to be found). I am going to try to use a Powerglide back-lights switch with my 54 Hydra-Matic. Otherwise, I'll use a switch like yours.
