ok for about the past month i havent been able to figure out whats wrong with my car. Right now it hesitates throughout the rpm band but not all the time, (sometimes the car feels fine) and when ur going around 48mph and give it 1/4 throttle you feel some sort of stumble. I am also having a rough idle while in drive and at a stop. I have brought the car to the chevy and to a local shop that did all the work to my car and either couldnt tell me what is wrong. So let me tell u what i have done so far. to begin with the car has all new wires, plugs, msd coil, and opti spark. the original plugs i had in there were the ngk tr6 gapped at .035 cause i was gonna run nos but then decided not to. so i changed the plugs and put in the ngk tr55s gapped at .055. after i did this it seemed to get a little worse. the shop that did all the work to my car told me that its my trans, and that it has torque converter shudder. I dont entirely believe this. there is no ses light on and i have run my scanner and not getting any codes. I put the stock mafs back in and im about to put the lt1 knock module back in and the stock coil. Please anyone with any possible ideas get back to me asap before i decide to blow this thing up!!!