billet head question

I want to buy a billet head for an srx. The web site I want to get it from say the stock heads are 26cc, but all they have for options is 24cc,22.5cc, and 19cc. Why is this and which one should i picK for what? thanks

Start off with the larger one if you just wanna run high octane premium 91 octane fuel, if you go to the smallest you will prob need to run racing gas, pick your choice, but the higher the compression ratio, the more HP you will make.

I don't think you will get heads for the 600 SRX if that's what you want them for. You could get some race inserts and machine them for your bore size and the compression you want to run. Billet heads are nice for the additional cooling and looks but if all you want is an increase in performance you can just mill .010 or .015 off you stock heads depending on your altitude etc.............SRXtreme