I' go for the 0# cap and not risk the radiator whats the risk of using a little water over loosing the radiator . Afer runing a 46 chevy over 532 miles and looosing less than a quart of water throught the Bosten mountians of Arkansass the presssure cap seems usless. The old truck my buddy and I ran was put to the max of It's maximune work level and never got over 195 on the temp gauge.
