I want to make a killer 600. Does anyone have any ideas or combinations I should use. Porting? Single or Twin pipes? Head work? Gearing? *Please help!!

I run a 99 600 with a cut head and base gasket shim to raise the port timing. It also has a mild clutch kit in it that gives it a quick accelleration off the line. I linned it up with a 98 fIII 700 and a 98 ultra 680 tripple. I took both sleds off the line by about 2 lengths and held that through to top end, they said they weren't gaing any ground. Over all the sled runs about as strong as a mxz 700 with a bit more botton end.