what the heck R U guys talking about? :confused: the rad cap? [which should be 4#, and should be available at any auto parts store] never seen any kinda "relief valve" in a task force rad beyond the cap, which when it gets above its pressure rating, lets the pressure off thru the "overflow" - if the cooling system is in good repair, and you don't overfill the rad, that function will not be used, but if it runs too hot, it'll [censored] a bit of water when you shut it off and the temp goes up a bit
w/ a good rad and such, a 7# cap will work too - specially w/ a small block
Bill