I think you're experiencing the infamous "EGR Stumble" (lean stumble) very common with the 4.9's.
First off, I'd check the Coolant Temperature Sensor circuit (at the water pump) to verify it's functioning to specification.
If that check passes, then check the throttle body gasket to see if it's been sucked in....causing a vacuum leak. Don't forget to check other obvious known vacuum leak sources as well while you're at it.

If the TB gasket is o.k. (I'd replace it if your going to check it), and you can't locate find any vacuum leaks, try this:

Disconnect the vacuum hose at the EGR valve and drive the truck around for a while and see if the bucking and kicking goes away.
If it does, then you can do the "EGR Restictor Plate" (search this forum for a bazillion posts about it) which is a "band aid fix" or find the REAL PROBLEM which would be an unmetered vacuum leak.

I've done a version of the EGR Restrictor Plate fix, and it did fix MY stumble/ bucking problem, however I do know that I have a pretty severe vacuum leak in the throttle body where the throttle shaft is (both sides too).
A rebushing of my TB should take care of that vacuum problem.

And if you still are having the bucking/kicking problem you may want to check your computer.
Click this link:A9x ECM's (and same years ECM's) Failures Due to Age
The capacitors in my '94 were leaking and I did the described repair which cured a random missing problem I was having..........however, it did take me a couple of attempts to get the repair right.

******Note: My computer NEVER showed/stored any codes related to the leaking capacitor problem I was having******

Good Luck

Bob