I read a posting on here some time back where it was suggested that b18 drivers should use a 7 psi radiator cap. I have the correct cap from the standpoint of depth, that is, it goes down into the radiator an inch or so. But it's a 4.35 psi cap. Where can I find a 7? Significant because I am using a 180 degree thermostat and it boils over when I shut it off unless I cool it with the heater.

Or maybe I need to change the thermostat to a cooler one. But I hate to, because the thermostat used to stick open and I hate that cold running.

Poor logic I guess, but there is my problem, and I would welcome any comments or suggestions. Mine is a weber conversion, everything else stock.