Hello, I had a dyno tune done on my pick up yesterday and it shifts fine under normal acceleration but at wot it shifts hard from 1st-2nd and only at wot it will not shift from 2-3 without letting off the pedal just a little.tuner said I need a shift kit but it shifted just fine prior to the tune.its a 1990 Chevy 1500 short bed step side with a 6.0 lq9 swap with a 4l80 trans and drivebtrain. I wouldn't think a 35whp increase would require a shift kit. Any help would he greatly appreciated. Here the before and after Screen shot he sent me.thanks.