Insignificant as it may actually be, a weeping water neck can be an infinitely frustrating and nagging issue that ranks right up there with a seeping valve cover or dripping differential. We’ve tried original, billet, and parts store versions with a host of different gasket manufacturers and sealers only to see short-lived success. We’ve even tried a bevy of bolt torque specifications and belt-sanding for flatness, but a little green stream always ended up getting the best of us.

Even the slightest of leaks can be surprisingly troublesome. With the engine off, coolant is prone to run down the front side of the water pump and drip onto the crankshaft pulley. Upon startup, the radiator fan is happy to distribute those drops all over the engine, K-frame, inner fenders, and hood, leaving a thin, sticky film of the stuff that’s supposed to be inside the radiator.

Tired of the thermostat housing humiliation, we reached out to Mancini Racing for the end-all solution to our problem: Billet Specialties’ O-ring water neck (P/N BSP90820). The real magic here is not only the meaty, thick construction, but the replacement of a standard gasket surface with an O-ring groove. The O-ring design eliminates several pitfalls of a gasket and makes the housing easily removable without the mess of stuck-on gasket material. After installation on our project ’67 Satellite, we’ve yet to see a drop escape and that faint aroma of antifreeze is finally gone.