Thanks,
It was actually a pretty simple soldering job, the machine work was just bandsaw, belt sander, and a hole saw. Did use a lathe to make/modify the drain fitting to look about like the original, not a necessary step for function though.
I wanted brass because the original rusted out, wanted this one to last. Was going to roll a can and make a seam until I found that cartridge she'll in my brass stock and it happened to be the right diameter plus and minus a tiny bit of taper from 5".
The one I made actually does hold pressure, it is open to the full radiator pressure connected by a 3/8" hose and the tank has the pressure relief cap. That's the way it works on a GMC 860 and some other old trucks, I suppose like new stuff too.
If the pressure relief cap is on the radiator then you don't need the surge tank to hold pressure.
