JJMYERZ, by about 60,000 miles the stock Rover cams shot as well as the lifters, this happens on well maintained vehicles also. The gradual wear is not noticed over the long run in performance. Plastic tooth timing chains, another Rover idea is trash also. Edelbrock true roller timing set for V-6 Olds will fit. I don't have the old box at the moment for part number, sorry. Replace the cam with a Piper cam thru RPI they are great, last forever and will pass smog, depending on choice of cam that is. On valves Rovers been doing a patch job like grooves cut in the stem to grind off carbon to prevent valve sticking hence burnt valve. This is another crock of s**t repair by Rover. They changed the exhaust valve three times in one year. Yankie designed motor, Yankie know how to repair. For a full valve job, minor port work and head surfaces milled cost me $845 three years ago. Carl...........o&o>........................