15-20 years ago, this thing was cutting edge. It belongs in a 90's neon themed machine. Way cool for an old stock cylinder set up. I've still got my old 7mm big bore stockers and just can't seem to justify the cost to get them set up again.
Those are all I'll run on my ice bikes. There was a sketchy incident running 20" studded tires on a -2 swing arm that destroyed my boot and left my ankle pretty sore. From then on, it's gotta have a solid plate back there for me.
If you do the Driveline set up, it will actually help in woods riding. It'll act similar to weighted flywheels like the GNCC guys run on two stroke bikes. The real bonus is getting to run much softer springs on the clutch.
OEM is about all there is. I've only seen a custom shift arm on a drag bike and it was one off. The stock stuff should last a good while. If you need that much spring pressure, try a lock up and softer springs. They are far more ridable that way anyway.
^ that. How big of a track? 1/2 mile ovals, go Shearers or CPI. The CPI will have a tad bit more grunt if you need it to come out of the turn harder. If you're running real short tracks or twisty TT stuff, try a set of SLP's or PT's. T5's are a little lazy for my taste.
Yes they are supposed to help with side loading. They should be ran with TZ style (Cylindrical) bearings. Stock is 2.86, going to 2.68 is typically for guys needing more MPH on larger motor set ups.