I am working on the 350 for my 32 pickup. I have a used Marine Crate motor that needs a little freshening up. The heads need new guides. I have an old Winona Van Norman guide kit that uses the Helicoil looking bronze guide inserts. These being marine heads, they have 3/8 stems on the exhaust side. Does ANYBODY know where I can get say 10 of these inserts without buying a whole box(50) @ $80. I havent been able to find anyone that sells them on the internet except Goodson. I guess I could call them and ask for a smaller quantity.