timing plate and cool head

[xXBlessedWithDeathXx]

I run 19cc domes with 93 oct and no problems.

[2003LimitedBanshee]

The only way to tell for sure what octane gas you are going to need is to do a compression check after making the swap. I live at 2000' and with 20cc domes I kick over 170 psi in each cylinder. So, needless to say, when I go to the dunes (at sea level), the only type of riding I do, I run race fuel due to the added compression (over 190 psi) and 4* timing advance. Bottom line, we can ball park it based on your elevation, but you really need to check it yourself, on YOUR bike to tell for sure. By the way, probably a lot of people know this, but assuming this is still the same, the heads retailed by Jeff (GREAT guy) are manufactured by David Noss (SUPER GREAT guy).