'98 2dr 4WD miss and lung at 1900RPM

[Landchipper]

I need some assistance. My Tahoe is the 5.7 engine auto/OD tranny. At highway speeds with the rpms at approx. 1800 to 1900 the engine seems to have a severe miss and the truck "bucks" and lunges. No codes show up on the computer diagnostic. I have replaced the O2 sensor, the coil, the dist. cap and button as well as tried all octanes of fuel. The trouble seems to occur when I begin to go up a slight incline in the highway when the engine needs to advance timing and unlock the torque converter to gain more power. I will give any other information that is needed for your help.

Any ideas will be utilized with great appreciation.

Ooops; absent minded me. I hit the wrong section. Sorry I will repost there.

Thank you for your expertise and patience.