I had a 95 6.5. Two or three lift pumps and a new injector pump, finally found the real problem was the FSD. Chevy mounted it at the back of the engine on top of the manifold and the heat would crack it. Once the fsd was moved away from all the heat, no more problems. FSD cost around $50, took 15 min to change. New injector pump was around $1800 and took a day to change. Which one did the dealer want to change?I've had 4 or 5 of them, starting with the one I bought new in 1982. All of them were good, but certainly not a powerhouse by today's standards!
6.5's were plagued with thatdam electronic injection pump that failed all too often! Not all of them had that though.
SR