2000 Ram V-10 bucking and losing power

Hi, I have a 2000 Ram 2500 with a V-10 that always has been a real workhorse, towing an enclosed trailer, car, and a load of supplies for years. 103,000 well taken care of miles. It always had a hesitation under part throttle uphills with no load. The guys at the Dodge dealer said not to worry, that it was just between its "low speed" and "power" circuit. They said just to put my foot in it more. Lately, it has been doing it while pulling the same loads uphills. Bucking and hesitating. I have always been able to keep up and sometimes even pass my buddies diesels, but lately the old girl just ain't what she used to be. I am thinking it it some kind of sensor. Replaced the spark plugs and wires lately. Normal checkout everything looks OK. Anybody have any ideas. Thanks in advance.

Timing chain?

Mine has 206k on it. And i cant say Ive ever had any issues with low power.

Other than taking a few seconds ( like 2 or 3 ) to build oil pressure at 1st startup ,mine runs like a top

Mine 96 V-10 would do this very thing. It was the O2 sensors. They would lean the truck out & under load (with trailer etc) up inclines on the freeway, it felt like I took my foot off the gas rather then push down further. With cruise set it would do it even worse. Changed them out & everything has been good ever sense.

Thanks 6pkr, makes sense. Will look into that next week.