Can I put a "pressure" cap on my original '49 radiator or will it let go and burst ? It had a slight tendancy to run alittle hot (highway or idleing) in the summer , and I just lived with it . 180 thermostat and it sometimes would get to 215-220 in summer then I'd shut it down . Now (winter driving) it stays cooler BUT I noticed the inside of the briether and valvecovers are milky-yellow . Should I put in a warmer thermostat AND a pressurized cap - Can't afford a new radiator yet and don't want to mess this one up , yet .
