Wierd stutter/hesitation sometimes

[TexaBamaBass]

1999 GMC Sierra 1500 5.3 Z71....For about 2 months now my truck gets a "stutter" like a small series of jerks, don't know if its engine or tranny, not sure how to describe what it does. No service lights come on. It almost always but not 100% of the time does it when going up an incline. What the heck is going on so I don't screwed at a mechanic? I recently put new tires on, went from 265 to 285, would that cause the problem?

[GM-Tech]

Could be a torque converter (TCC) shudder or an engine misfire. Next time you're going up an incline and the problem is occuring, LIGHTLY touch the brake to disengage the TCC and see if it goes away. The TCC problem would not happen during in town driving, so if happens then too, it's probably not TCC.