Dogface huh, oh well On page two of the tech forums, there is a post for "new carb install" On that thread, rosseti posted a picture that you should look in to. Hopefully that'll help you. I ran a non-orig TH400 for some time and just let my shifter do the talking, but what you want can be done, one way or another. Good luck,
Lokar makes a kit that will do this job. I'm still looking for an original kickdown switch for mine.
You run 12 Volts to a switch on the carb or under the throttle pedal that closes at nearly wide open throttle. The other side of that switch runs to the solonoid on the side of the TH400. When you are WOT, the solonoid in the TH400 operates. It downshifts the TH400 for you at WOT. You can do this manually with the shifter. Some use to call it "passing gear".
John's way is a good solution You can buy miroswitches from www.digikey.com Current through the solonoid is 1 amp, so pick a switch with 3 amp or higher rating. A bit higher rating is desirable because the load is inductive.
