Cal, you can buy OEM boots that will handle ethanol for decades and fit in the OE metal shrouds from 650 Central. If you use JBM boots be sure to retain the OE air box or otherwise support the backs of the carbies. Don James is a good man and I'm sure he didn't mean to misrepresent his product, but his experience is mainly with light carburetors on ultralight aircraft. With the heavy BS38's, his JBM boots will crack at the spigot stops if used without support. Anyone who tells you otherwise just hasn't used them long enough, it's going to happen.