TO stroke an engine properly your looking at a minimum of $1000 to do rite. It requires a rod kit, knowing the range of piston weights you will be using so the crank can be balanced correctly. Crank alone will cost you better than 700. It will make more low end power, BUT can reduce RPM you can run at for peak power this may or may not be a good thing depending on your pipe setup and other variables.
It requires Different porting, due to the stroke this is a major reason most 4 mil Hondas run like a turd. It may change where your cylinder needs to be placed (spacer plate) depending on length of stroke. It will require a nice set of cases to be clearanced for the rod due to the location of the pin some engines do this mod themselves when the washers let go
. Stroking 2 mm is not worth the added effort, 4mm I guess well see, up to 6 is possible, anything beyond that probably wont fit without sealing issues unless major welding of the cases and re machining is done $$$$$$.
Unfortunately Kawie and Suzuki got hosed by the aftermarket from the beginning. Honda got all the cool aftermarket stuff for cheap. You can build a 4mil Honda big bore from ESR for under 1200. I cant turn on the lights in my shop after buying the parts to do a LT for what they can sell em for ready to run. Hell even a Kawie you can make a 317- 330 for 500-1000 with just a piston and Rod change no stroke at all.
You have to really love a Suzuki to bother. But I guess that why were here.