Once you have crank position locked for your new timing marks measure depth from top of sleeve to top of piston. Next, transfer the inside measurement to the outside of the sleeve, mark with scribe, and start cutting!
For crank induction, remove the carb, turn crank to new open/close timing and scribe a line on the crank. Remove crank, cut, polish edges, reassemble, and go run!
Works for me!
