I rode a 19 for a while and loved it on the highways. My only gripes were if you're not careful to rev it a bit too high for the launch, it induces the occasional conkity conk noises from the con rods etc. on start ups, which would likely leave some metal dust in ones oil. I have a couple million miles of "the less throttle on start up, the better" branded into my brain from my truck driving days, including the recent electronic truck engines that require absolutely no throttle actuation (aka 'idle away technology') for clutch engagement, even on the steepest grades. I guess old habits die hard. The other concern I had was you can hear & feel the engine working pretty hard on the hills with the 19. You have to keep it tached up pretty good or the engine grunts pretty hard. Just my little two cents, but if we asked a drive line engineer about the 19s, (vs. a 42 rear) I bet the answer would be don't do it. I could be wrong. I've since switched to the 18, and it's more forgiving on launches. If you tune for max HP with a 12.x air to 1 fuel type rich mix, the 18 & 19s are a bit more forgiving on launches. A 17.5 would be nice too.
