since i purchased truck about a year ago i have not like how converter locks up, over 50 mph and have to let off gas to get it to lock, hooked a scanner up and pcm asks for converter lock up as soon as truck hits about 45 mph, when converter does lock up it is tight and doesnt slip at all i can lug it very hard, trans does have some kind of performance rebuild from a co out of jersey but i forgot the name, was done before i purchased, any reason why the converter wouldn lock up as soon as pcm commands it to

 

Mine locks at around 55 mph. It actually locks quicker if I accelerate just over 50.

 

but shouldnt it lock up as soon as pcm commands it to