i was told i need a lock up switch for my 700r4. my tranny is fully race built has 2 tranny coolers, the radiator one and an external one. i was told my suppling +12v to a pin hole on the tranny this will lock it up when i flip the switch is this true, iv driven the car bout a 100 miles and have had 0 problem, do i even need to lock it up, the stall is a fti street brawler 2400

 

Several options ; you can use a internal switch that needs no input from you at all , automatic lockup in 4th
https://www.thirdgen.org/forums/carb...c-control.html

Up to you ;
trans runs cooler and you get better fuel economy

Google lockup convertorr

 

so A needs a 12 volt and b needs a constant ground if im gonna use a manual switch? and not using lock up wont make the tranny go out will it?

 

im just gonna go 12v in pin A since me and possibly my friends are the only one that will ever drive it, what stall shud i run in between 2500 and 4000, how will 2500 perform i really dont wanna over heat it, 4.10s or 4.56s in a ford 9inch in the future with a 400sbc or bigger , and are you sure a 12v will lock it up?

 

A needs switched 12V switch

 

and thats the only pin that needs anything? i assuming cuz the tranny is grounded

 

Trans may be grounded but nothing to say the switch ( more than one type used) you are dealing with
is grounded to the trans

AS stated in the link I posted for you above
"The external wiring stayed relatively constant in all years, regardless of what went on inside.
Power through the brake switch on pin A, the ECM switched ground through pin D to lock the TCC, ;

in your case you would put the switch on the wire to ground coming from D