Valves can be sourced anywhere as mentioned.Almost everything these days is just a SBC valve, or some derivative of one. You can typically make an easy swap out to 11/32 because a guide liner can be used, and its close on size to the 3/8" bore currently. You can also go with full bronze guides if you think thats what you want, albeit more costly.Reducing some area of the valve stem, and reducing valve weights are both good efforts. Dwayne could answer of the top of his head I'm sure, but I have flow comparisons on W2's at the shop, along with RHS/Indy and Enginequest, showing 3/8 vs 11/32 valves. Some arent as big as an advantage as you would think, but I'll take the lighter weight anyday.