Originally Posted by jcoop

SO this is the car that I've done the engine swap in. The car has a rebuilt 722.3 automatic transmission. Two days ago I replaced the shift modulator with a brand new "upgraded" unit. Now, it shifts very well through the forward gears. It goes into Drive and Reverse with authority and without hesitation. The problem is when going over hills... (this issue is kind of hard to explain). When you crest a hill going around 25MPH and you're not hitting the throttle, the transmission will shift either up or down depending. Now, here's where the issue lies. Whenever you resume acceleration, the engine will rev up before catching and/or dropping back into gear. It's almost like the transmission sits between 3 and 4 in neutral and when you hit the throttle it shifts one way or the other back into a forward gear. The transmission has the proper amount of fluid (Valvoline max life) and when I put the car back together, I changed out the filter as well. ANY IDEAS??