[DeTomaso] pressure and overflow tanks

[LEVITT1946 at aol.com]

Dear Friends ,
On a 1972 Detomaso Pantera  what is the recommended cap on the  pressure 
tank and the overflow tank.
 
I had a 13lb pressurized cap on each tank and car seemed to hold its  
pressure and temp. Last night I changed to a 16lb on the pressure tank and a non  
pressurized cap on the overflow. The car hit 250 degrees in traffic and 
stop and  go. 
 
Should I put a 13lb pressured cap on both tanks or a 16 lb pressured cap on 
 both?
 
Robert
Team Pantera Racing #3196
Gumball3000 #56 
 
check out this link of the gumball pantera against dodge  challenger rt 
 _http://www.youtube.com/watch?v=SDg2EzokF60_ (http://www.y
outube.com/watch?v=SDg2EzokF60)