I've never had an overflow tank before. All these years driving these things and I just accepted you added a little water now and then. Since I am putting so much effort into this build, I decided to add a 13" stainless overflow cylinder. No idea if it matters or not. I have been told all these years to run a 4 pound cap just as insurance. No idea what that means, but its worked well. I am not a scientist, just a driver and part time backyard mechanic.
