I highly recommend doing it, now. To check them is a no-brainer. To adjust them isn't hard, just a little time-consuming. I had 1 exhaust valve that was on the tight side and I let it go for a while because it was close to within spec. Well, to make a long story shorter I finally put it back in spec and WHOA, it was like I added a turbo charger to the thing. Take the little bit of time it takes to check/adjust. You won't regret it.