do new cylinders come with powervalve and all?

[Nevada Sixx]

hi,,i think i'd like to have two cylinders, one stock , and one ported for when i ride in woods. do they cylinders you see in the magazines come with everything i need to just bolt it on? or will i have to take out powervalve and stuff from the stock cylinder and put in the new one? thanks.

 

[los36]

just the cylinder. no nuts, bolts, springs, gaskets or power valve parts.