One suggestion, get a radiator cap with 12 or 14psi rating instead of the 16psi
Assuming you are using coolant, boiling point doesn't drop that much and your repair may last longer with lower pressure in the system
Engines generally run between 190-215degF, but can go up to 225F when under load, i.e. climbing a longer uphill grade or pulling a trailer
Boiling point of 50/50 coolant/water without pressure, no rad cap, is 226F
With 8psi pressure it is 248F
With 12psi pressure it is 259F
With 16psi pressure it is 267F