Light radiator overflow
Hi everyone, I just joined and am really needing a good logical answer to why my 71 GTO 400/400 is spewing a little overflow after running 5 minutes or so. It is not a violent overflow like overheating but an annoying 2 or 3 ounces. I have replaced the radiator cap and also put in a new Delco thermostat and neither has solved the problem. I was thinking that maybe I could just add and aftermarket overflow jar and correct it but that would not be original.
I have an original car with only 54,600 miles and am trying to keep it that way.
Any help or thoughts would be greatly appreciated