Truck is a 91 k5 with a 5.7L. For some reason when i am doing about 60 or so. the 700 seams to drop back to 3rd a lot. I dont drive fast if that matters. At 60 i thought it would stay in 4th. Even if i tap the gas a little drops to 3rd. I know very little about this trans. my other trucks are 400s and no computer. SO could it be something with the TC? As always any help would be great. thx!!