My last motor broke a Manley SS Exhaust valve and I am running water injected Bassetts, however I don't know if this was the cause. I do know that it was expensive to fix, and now have the water injection set to "mist" out the back while under way. So far no problems, except for the occasional burn that happens as a result of contact w/ those headers. I did run O/T dry headers, very hot (and loud), and even after wrapping w/ thermal tape, still too hot. I do like those jacketed thru-transom headers and would like to try them, but they are expensive. Anybody running those?