Radiator cap preasure?

[bilden]

When I went to get a new radiator cap for my 92 EB 4x4 auto trans., Autozone showed it should have a 13 lbs. cap. I called Ford and they said they should it should be a 16 lbs. (RS-90). I currently have a 13 lbs (RS-77) on it. Should I go with what Ford says or Autozone. I have had problems with the Stant's thermostats in the past and that's why I was going to get an original Ford part. I just got done replacing the thermostat, fan blade, and fan clutch becuase it was running on the hot side, but now the temp gauge doesn't even get to the "N" it made a big difference. Anyway, any help will be appreciated.

 

[mrboyle]

I would go with the Ford 16lb cap. The higher the cap pressure the hotter the engine can get before the coolant reaches its boiling point. The 3lbs could mean the difference between a blown head gasket or just getting hot if there is ever a problem with the cooling system.