Ok, so I recently just rebuilt my engine with a 70 over bore with Wiseco piston. I also have a D&G pipe, 1/2" reed spacer, stock carb, and custom open air box. No clue what size jet is currently in, but what is suggested?
To be safe, I would start on the fat side and work your way down. Mix your gas 32:1, and put a 290 main jet in it. See how it reacts to that. (Spark plugs are cheaper than rebuilds!)