When I rebuilt my 350, the exhaust valve rotators went back in. I'm not sorry, but am now wondering if I could have left them out and just shimmed the springs. The heads are "993"s without any seat work except grinding. I twisted it up pretty tight a while ago and may have floated a valve or two without any damage. (It had hydralics then, now it solids) We put about 8000 relatively easy miles on it a year and the performance is what I expected. I'm thinking I could get some more "Rs" out of it without the extra rotator weight, but don't want to tear (or burn) anything up. Should I keep them?? Thanks Kevin (Spring is coming soon!)