Radiator cap

[Tom Warner]

Am in the process of replacing the engine coolant of unknown type
with 27.5 gallons of Fleetcharge coolant. I noticed that the
radiator cap is a little tired and replaced it with the same one a
7PSI cap since I figured that it is the correct one. Looked in my
Detroit Diesel factory manual and it recommends that all on road
engines use a minimum of a 9PSI cap. Just talked to Shane Fedeli and
he also has a 7PSI cap installed and his factory manual also
recommends the 9PSI cap.

The blue box owners manual does not say what kind of cap the radiator
takes. Is there a reason that BB used a 7PSI cap instead of the
recommended 9PSI cap? What is everyone else using and is this the
original BB cap? Seems to me that the 9PSI cap would result in a
higher temperature to be safely reached if there is a problem before
the coolant boiled.
Tom Warner
Vernon Center,NY
1985 PT 40 with a 6V92