It appears the trans go picture above is incorrect for the pin assignments, that sure was confusing. This is from a GM manual page for 200c, 250c and 350c
Is the wire I am calling orange actually tan with a black stripe? Must be half color blind here. If it is I think it goes like this:
A - Purple is +12 volts and went to a switch on the brake light switch (when brakes are applied the power would be switched off.) then to a +12V source.
B - Green with white stripe is the 3rd gear switch to the computer.
D - Tan with black stripe is the TCC solenoid ground controlled by the computer,
It looks like the kit you want to use would go to A and D and would be correct but you would have no 3rd gear switch so it would want to lock up all the time.
Pretty sure you could hook D to B and ground through the 3rd gear switch and that would solve that. Would also keep the brake switch on the +12V if I was doing it, and perhaps use a vacuum switch like the trucks and pre computer cars used so it would not lock up if the engine is under load, or when the transmission is not in 3rd gear or the brakes are applied..
Non CCC TCC setup. (Thanks to ribbedroof who originally posted this diagram here.)