To start off i want to say thank you ,i just put a set of heads on , had a machine shop check for cracks and surface check , everything checked out fine , installed new valve seals , got everything installed and fired up and runs very well and no leaks , but , now i have this lugging or jerking going on , did not do this before , the only thing that i did not do was reuse my original injectors , these heads came from a salvage yard , now i'm guessing i probably should have , or maybe not , it is a standard shift and when i drop a gear it does help , but like i said before , i didn't do this before , i know you guys can , you were right on with my first problem and kept me from getting rid of the truck , again thank you .