Just get some custom domes cut for your setup. Changing base gasket thickness changes your port timings. If your cylinders are ported, ask whoever did your porting what size base gasket you need. Assemble the top end and torq the cyls down and check your squish, if its too loose with the appropriate base gasket, then you need to get some new domes cut. Call up your builder or dave @ noss machine and he can custom cut you some domes, but the dome profile will greatly depend on your porting and other setup variables. Fuel type, pipes, style of riding, etc etc etc
Call kevin @ HJR, he can help you out with getting everything set up right. His number is in my signature.
- Jared