I don't have a definite answer for you on the Napa dampner, but I've just started looking for a three row dampner for my 292. For normal street use, I think it would be hard to go wrong with a dampner, as long as you keep one on there, unless you've serious modified your engine, that is.
On mine, the rubber is starting to come out the backside, though I may reuse it. Is the one you're looking at have 2 or three grooves?
