Just thought I would share a fix I did for a radiator neck. The threaded portion of my radiator neck was split in 2 spots down the threads but not farther down the neck. It would not hold the cap in very well. My fix was cheap and easy and only if your looking close can you see it. I took a pipe that the inner diameter was close to the out diameter of the top of the neck and cut a 1/2 in piece and turned out the inner diameter till it fit tight over the neck and held the threads tight and painted it black. Now the cap hold tight even when I put a motometer on.
That's good old yankee enjanuity.you win the cupcake for a neat fix.was the pipe a chrome sink drain?it looks a perfect fit.
Give that man a cookie !!!