I believe that on an NPT fitting, the 1/8" refers to the inside diameter of the fitting. At any rate, they work perfectly with Vans manifold and that's how I've used them!where I got the 5/8-28 size --- their online store now calls them 1/8 NPT -- sure don't look like 1/8.
Ron
I have not been able to find hose fittings to fit the Kavlico fuel/oil pressure senders =- weird thread size - 5/8-28 -- would like to hook up to AN hose fittings. What have you folks done?
Thanks,
Ron