1995 Suburban engine misses

My 1995 GMC Suburban has an engine miss at partial throttle cruising and acceleration. I have changed out the fuel filter, checked the air filter, the dealership supposedly did a troubleshoot on it and called for the intake manifold gaskets to be replaced, did that this weekend, along with throttle body gasket. I reset the ignition timing. I have added more fuel and a fuel additive to clean the throttle body injectors. Still it misses. I get no check engine light. Any suggestions out there?

Welcome to AF. You should have posted this in the Chevy group, Suburban section. Anyway, is this miss driving, under load at idle, is it a dead miss, how are the plugs and wires, can you pinpoint the cylinder shorting one at a time and see if there is no change? Lots of info and diagnostic steps missing here.

Our '99 Chevy Suburban did the same thing. It has a Vortec 350. It was especially bad on humid or rainy days. Turns out there was a hole in the distributor causing spark to not get to cylinders. Good Luck.