hay there hr57 have you gone back to bacics how old and what condirion is the radiator sounds like it may be partialy pluged also does it have the ca pacity to do the job a combination of old radiator and marginal capacity has plaged us hot roders for years have a good radiator shop check it it like chicken soup it cant hurt good luck ted I KNOW ALL THE RULES AN I KNOW HOW TO BREAK EM