Hi ford guy 2,
Tom, JW, & Patrick are correct -- thinking backwards at 02:29 a.m. after finishing repairing my lawn mower.
Because of a 3:27 speedometer gear adapter in the way of the cross-shaft, had similar problem with 30-31 switch & recently posted this on 04/29/13 under title of:
"3:37, speedometer gear, 1930 Brake Light Switch
7. After brakes & everything else adjusted, installed a new 1930/31 brake light switch with all new wiring. (Car came with a 1929 top of transmission brake light switch).
8. After installing the 1930/31 brake light switch, the front tip of the switch rod did not move far enough to the rear to turn the brake light switch "OFF" when it touched the rear tip of the pedal to cross shaft rod. (Needed a minimum of "approximately" 5/16" movement to the rear to turn it "OFF").
9. Solution: Either add on to the rear of the pedal to cross shaft rod or add on to the front of the brake light switch rod -- chose adding to the front of the brake switch rod.
10. Placed the rear flat end of the brake switch rod in a vise, & threaded the front part of the brake light switch rod with a 10-24 die.
11. Screwed on a 10-24 nut first, followed by a 10-24 coupling nut, followed by a 10-24 round head screw with lock washer, screwed into the coupling nut.
12. Adjusted front length of brake light switch by cutting length of coupling nut & cutting length of the 10-24 round head screw to bottom out on switch rod.
13. Drilled a 1/2" hole through new corner brace "stop" (this added because of 3:27 speedometer adapter), & the chassis cross frame to allow coupling nut on switch to move back & forth.
14. Everything finally worked -- ordered a new A & L brake light switch today & will modify same with die & coupling nut.
(The Chinese made Home Depot 10-24 "Bolt-Pro" coupling nut threads are too large - bought U. S. made coupling nuts at local hardware store).
Hope this helps.