need answers on radiator caps

[ford]

hi

just wondered what pressure radiator cap the eb to au should have as the ea 3.9 uses a 110kpa/16psi recovery and ed to au 4.0 uses 120kpa/17 psi and ba to fg uses 120kpa/17psi recovery cap

those specs above is what ford specify

would using a 120kpa/17 psi or a 125kpa/18psi cap be ok in the eb to au

what causes a hiss for a couple minutes after a drive at times with a 110kpa cap on a e series 4.0 will a 125kpa cap fix that or do they damage stuff

how much difference is 18 psi over 16 psi

and how much difference is 20psi over 16psi

[Ef_frmnt]

Must be all the boost pressure leaking out. Turbocharged cooling system running 16 psi.. yewwww