The vacuum switch is getting real hard to find. The pressure switchs can be gotten at most trans supply places for about $6.50 ea. They are from a 350 turbo trans and come in a varity of pressures. I used 45psi for od and 50psi for for lock up. 1psi is equal to 1mph. I supplied the vacuum switch power from a toggle switch on the dash so I could kill the od when I wanted to. Most of the time I leave it on but for towing or racing I shut it off.