Not sure about power. The pros will have to help you on that one. I know that there a lot stronger and more durable since there billet. We have 3 of them(not for sale) sending 2 off to Carlos to tomorrow to have customized for a 310. They also keep your bike a lot cooler. In my option if you find one for the right price It's well worth it.

 

Get the cool head and the o ring head gasket setup, it's awesome

 

Definitely get the o-ring type gasket. Works amazing. Having mine converted.

 

They have interchange domes which is nice. I went to a 19cc dome and I notice alittle more pep on the lower end.

 

The smaller cc domes will give you a bit more low-end power from my experiencewith them,but just remember if you go with a low cc dome u might have to run race fuel,which in one way is better because of the crappy fuel(harder to jet or tune bike) we get nowadays.

 

Only problem with race fuel is it cost $10 a gallon

 

Stronger Billet head, less warpage than OEM.....do you really need a CoolHead, not really, just a nice to have IMO. A good example is Tom Decrescente's ATC250R at 68 MM bore....runs with all the BB engines up to 370CC on the MX track, also runs a modified OEM head with a custom dome design....No CoolHead.

Carlos