Hi,
haven`t done this to my bike, two guys I somewhat know did.
One dragster-shop I know is doing such work on a regular basis.
It`s a german site which doesn`t matter cause the terms should be known to you. Just to get an idea:
http://www.kramermis.de
Anyway ,all three of them talked about stroked EVO`s, only.
88cu and up.
One used an S&S crankshaft-kit with JE-Pistons, the other Wiseco (???)
However all (including one pre-evo specialist) will balance it 60%.
Costs: static ~ $80 plus 2 hrs
dynamic: ~ $250 + 2 hrs
Apparantly, it makes sense to stroked bikes and for cranks which are ill-balanced by the factory and last but not least for cranks with foreign company conrods and pistons (such as above: S&S crank plus JE-Pistons).
Did they notice a difference ?
"und ob !" replied one (which means 'of course'

)
The pre-evo specialist explained that the shovel longevity improves a-lot even with stock engines, however he recommeded it for stroked engines in particular.
ray.