Like the title says I'm trying to install a mechanical coolant temp guage and the fittings that I have which are 1/2-1npt and 3/8-18npt, I know I could buy a tap and do it but would rather buy a t fitting for my d16y7 head and hopefully keep my stock temp guage, could I pointed toward the fitting I need or the size of the coolant temp guage in the head. Thank you