If you fabricate your own aluminum radiators or swirl tanks and require a quality filler neck that can be welded on, this part is for you. It is machined from a solid billet of 2 1/4" OD 6061-T6 aluminum and includes a thread-in nipple for connecting the overflow tube.
This is not a flimsy, easily distorted stamped fitting. It can withstand the heat of welding without warping so that the cap will seal properly when the job is done. Accepts any standard automotive radiator cap such as our Stant Radiator Caps, sold separately.