Welcome aboard 'TOB'.
Even as a mechanic you will find a wealth of knowledge to fix any and all issues from the folks on this site. I certainly have thru reading threads when the typical faults come up.
I had occasion to browse more recent model suvs in the same mode as the GMT360 and was not too impressed with the core performance advancements over the two decades. With the exception of mpg the GMT360 was comparable or even better in the underappreciated torque criteria. These vehicles (esp. engine) are finicky due to the combination powertrain advancements and out of box thinking at the introduction 20 years ago but when all is dialed in its an amazing machine and quite a brute for its time. With that said the smallest thing (ok some hard driving tbh
) can cause slight imbalance and mild side effects that doesn't affect performance but are mere annoyances. I instead just bought some quality parts, chasis grease, sprayed some silicone lubricant and contact cleaner here & there and wuala rides and sounds as smooth as new.
Hope you get many years of reliable and comfortable driving out of your truck.