trazz

I have a 1998 Camaro with frost tune off road y pipe yank 3600 converter and I wanted to change rearend gears so I put in 373s and I had a local shop set computer for gear change now my problem is at 85 mph the speedometer starts going backwards until I get off the throttle it reads correct mph all the way to 85 than goes haywire any ideas I'm lost