ok i am wondering is a 6mm stroker crank bad for the bike?? its bored 86mm over well i guess i should tell u the engine its a 350x engine bored to a 393cc and ported polished 11:1 compression, bigger valves and intake and exaust put in it and a cam put in the bike also.. oh the valves are titanium valves and springs well i need to know if the crank would be a good idea! thanks oh it strokes the bike out to a 430cc bike...

 

I have a 4mm stroker, in a 400ex. It vibrates a little more than stock, but not bad. The 6 would vibrate just that little bit more, but I think it would be fine. I have heard of 428cc 350x motors. That is probably the same bore and stroke combo. They are reliable enough, damm are they fast.

If you have the money I'd say do it.