i was just wondering what input the tranny uses to decide when it shifts. this would be on a 91' comache 4.0. i'm thinking the computer takes speed into account along with rpm and shifts accordingly. somehting tells me theres more to it though. is there any chance that a simple speedo gear change could trick the tranny into holding shifts a bit longer? i've got 31's on it and there's still plenty of power... it's got the "power switch" for the tranny that changes the shifts points and t/c lockup too but i was just curious to see if this is plausible? for example (not sure about this, maybe my theory is backwards but...) lets say you switch in a speedo gear to make the speed reading slower. as a result the tranny would think you were going slower and it wasn't time to shift yet. think it would do anything? like i said, i'm not sure what parameters are used so it may not do anything but i was just curious.