95badboy

I have a 2002 2500 6.0 4l80 recently had go have a new motor and used a 07 6.0 with the 58x reluctor wheel. I noticed that now when driving bout 55 my torque conv will engage like im goin up a slight hill with tow/haul on then sometimes it does fine it doesnt slip or shift weird by any means the dealership i had my motor installed messed with the computer to make the 58x wheel wrk idk if that can be the issue or not anybody have any ideas