Looking for some help. 88 3vze Auto 4.88 gears. While cruising right around 70mph, my truck suddenly drops 10mph, and rpms go from about 2800 to 2000, then sharply returns to normal. All within 1 to 2 seconds of time. It's done it 3 times now in the last 2 months. Today it did it once during a one hour drive on the freeway. Didn't do it before or after, just for those 2 seconds of time. Anybody have this happen to them? Im clueless. Thanks

 

Anybody?