SFO,
BTW, it's not man, it's girl.
The price for the stroker kit includes a new Yamie crank, so if you wanted to send yours in for the mods, it saves about $300 (maybe more, can't remember exact $). It comes with all the parts, including a piston kit, gaskets, etc.
The kit uses the stock length rod, and a shorter piston, so the angle isn't increased to the point it becomes a problem.
We did try a shrunk rod stroker on the 400, it was hard on pistons, like you mentioned, too much forward thrust with that ratio.
Reliability has been really good with this setup. We have a few that have been running in the quads, and they've looked great after 3 months of pro racing (torn down just for regular maintenance).
As far as adjusting the cams to work with a shaved head -- the only way to do that right is with a vernier sprocket. Even then it's an iffy deal because the timing chain has more slack.
As far as the way we ported the YZF heads, it's classified -- we still use it for our race engines, every little bit counts there :p
Jason, squish is a very technical term! It just sounds goofy. Your piston has a squish band. Squish can be used to describe the act of creating compression in a cylinder. It can also be used to describe that weird sound some forks make when they're compressed -- or is that squoosh? :confused: