I hope you folks with manual petcocks have over flow tubes. If not you are much more likely to hydro-lock the engine than with the auto petcock
I'll continue to beg to argue that as false..... All one needs to do is turn on/off the tap; my job as a ship engineer requires that I follow precise procedures over and over again without fail or forgetting.
With that being said I believe that overflow tubes are worth far more than their cost as the human machine is subject to failure too.
As to rebuilding petcocks with factory parts yes... Rebuilding petcocks with K&L no way!