Hello,I have a 94 silverado that set up for apprx.18 months.I got truck running last week,everything works great except transmission seems to shift at around 3000 rpm.I can make it shift if i let up on gas pedal at 2500 rpm.I checked fluid when i first got running and i had to add 2 quarts of fluid,no leaks anywhere.Any help with this would be greatly appreciated.Thanks,Karey