should valves rotate ?

I know when building for a performance application, the exhaust valve rotators are one of the first things that gets crapcanned. I don't think the valves are designed to rotate unless they have rotator retainers and or offset rockers like what Kit is talkin about. The rotators are much thicker than a standard retainer and would bring spring pressure way up on the exhaust side on a performance engine. Not the type thing you want.