[OfnaJoe]

My raditor pukes at 195 deg, had to finally put a overflow tank on. So now what lb cap do I need?
Modified motor with about 10.5 CR. Bored, heads worked,headers, big Holley..etc.., So I was thinking I need a heavier pressure cap now!

 

[Midlife]

13 psi is normal; sometimes, you can get away with a 16 psi cap.

 

[OfnaJoe]

I was thinking 16 would hold pressure longer, my 13 might just be wore out, Guess I be going to Auto Zone.........AGAIN!!!!

 

[JohnnyK]

What is the difference between the 2 (Obviously water boils at a higher temperature with 16) so wouldn't 16 be a better choice?

 

[Midlife]

13 psi is more forgiving for a coolant system; the 16 psi and higher may cause another component to fail at the higher pressures.

 

[66benchcoupe]

I run a 19 lb. on my 66. No problems.

http://pic20.picturetrail.com/VOL1600/689808/5028181/63985204.jpg

Robert