Torque Converter??

Hey folks. I'm new to your site but not to forums, I usually hang in a couple boating and fishing forums. I greatly appreciate the immense amount of knowledge and experience in these formats.
My problem is with a 1996 k1500 w/5700 vortec with 85000miles. When moderately accelerating from around 30-40mph, like on an entrance ramp, instead of dropping down a gear to the torque band it drops all the way down to first gear. It takes some searching with the peddle to find the right gear. Also while cruising just a slight touch of the peddle causes the truck to studder or hesitate.
I've just had a new water pump installed and was wondering if their was some kind of vaccuum hose issue hear that might have gotten disconnected.
I've also just changed the oil and air filter now the chk engine light is comming on. I can't believe all this is a coincidence.
How much is the standard torgue converter replacment? I'm open for opinions. Thanx.

what kind of transmission do you have? i don think they still use a vacuum modulator, so i dont think that would be your problem. if you have a 4L60E transmission, it could be an electrical problem.

have you done the update wire kit for the computer?

because in 96 trucks with the 4L60E tranny you had to get some kinda ground wire kit from the dealer its 26 dollars but its worth it trust me on that it costed aamco to rebuild that tranny again because like at 20k it burned up.....then at 10k miles after it was built for the first time it started shurding then at 15k miles it started sliping and then at 20 k it burned up

Nope, didn't even know their was a bulletin on the ground wire. Thanx, I'll look into it.

sounds like a throttle position sensor. very common..
Tim
Trans tech 25 years

Finally got my truck to the dealer after it's been running like crap for a couple months. They put it on the diag machine and said #6 cylinder is misfiring. Problem is they can't remove the spark plug to find out why. I told them to soak it penetrating oil overnite and try this morning. If they can't get it out I'm taking the truck back before they snap the plug off and really create a problem. I should have taken it to my regular mechanic but thought this one was for a certified tech. Truck has 85000 on it. Any suggestions would be greatly appreciated.

If they still cant get the plug off, it will probably need to be heated to get it off. Either run the engine until hot, or heat it with a torch. Ive done that with 02 sensors befoe and has worked well.