I have a TH400 in my pickup and have noticed that there is a hookup outside tranny similar to the 2004R and 700r4, except that it has one prong, is this the detent port? Would it make the tranny act like it has a 2-3rd gear flare up? It reminds of the the TH350 when vacuum modulator is disconnected. Where would i connect this port to? TIA