The standard bores are fine, and a lot cheaper. I think if I wanted more low end grunt, I would do the 840 with the stage 2 cams - higher torque lower rpm, could be wrong, but I think it would have more low end torque, stage 3 cams are for more top end, that is just my opinion. I had looked at other places for prices and FST Mickey can't be beat, sorry....just the plain fact!
I have the 840 with nothing else but muzzy's, so I am missing out on top end with stock clutch, just don't want to do any more work to it. Of course I have the 08, so also have a carb kit and TPI valves from Hunterworks.
Oh yeah, just thought I'd add this...still stock factory belt and close to 2,000 miles....:yahoo:
How do I like it, well I damn near shit my pants after getting her broke in and opening her up, I am serious. I've got 1,200 miles on the 840 and I beat the ever living piss outa mine...:93C_peelout[1]:
Not one problem....yet.