Based on my limited (very) understanding of both the issues you raise in the above post, the Stealth cams should move the powerband up the rev scale, which might work out well for your style of driving. Since you don't do a whole lot of slower off-road driving, you might like them even better than the Montero grind.

The original valve stem seals, which is what I'm guessing you are talking about, as opposed to the valve guides themselves, were a different part number for intake and exhaust. At "some point" they figured out that the intake stem seals were not good and now all the valves use what used to be just for the exhaust.

Unless you are actually talking about the valve guides themselves. I seem to recall there being a change to those as well, where the valve guides may have had an issue dropping. Not sure of the change or how/what was done about those. Again, my knowledge on that particular is pretty basic.

John B.