And if you go up in size you need to make sure that the hull material you remove to get the larger size valve installed doesn’t allow seawater to get into the core material (if it is cored below the waterline). Don’t expect the external hull gasket, if any, to stop the sw intrusion.
As others have said, best to stick with the original size valves if you want to replace them. But even better is to restore the oem valves.
BTW, Marelon was/is the gold standard for composite ball valves and thru hull fittings. I had them on a boat and they worked very well, although harder to turn than well lubricated bronze valves. Don’t know anything about the Trudesign valves.
David
