Radiator Overflow

[orlowted]

Never considered the radiator cap as a possible culprit. I think the one on the radiator now has been there through many engines? My engine does the same after I shut it off...Runs at about 140-160 while driving, then once I shut it down it jumps up. I will look at caps this weekend, but about the overflow...will that look right on a classic stang. Where have you put it in...on the firewall? Right now - I have the radiator as stock (3 row aftermarket) and the runoff hose just fastened along the radiator and then hanging below. Where should I mount the overflow? I do want to race next summer after the paint is on, so I think I will opt for Both - new cap and overflow tank. How big should the tank be?

Thanks for the help....

TJ