I was on the parkway last night, doing about 80 when I was cut off, I put it to the floor, the rpms jumped real high, and seemed like it was in neutral or something, the car didnt really pull... Now if you were to be driving, and not slam it to the floor, it will downshift, and pull like crazy... I think it might have done this a time or two before, any idea what it is? other than that the trans seems to be shifting fine. Its a 700r4 by the way.

 

check fluid level, check TV cable. If those are OK, one of your clutchpacks are going. if so you may be able to bandaid this with a set of corvett servos but be ready for a trans rebiuld sometime soon