as this car wasnt a 400 to start with (judging from the hood), you most likely dint have 3 items that were on 400 `s and AC cars...and when you put a 455 in it those would be required 1) X filler panels 2) lower baffle 3) rubber or 'masticated' fillers on ea side of bottom of radiator
If you have those...keep looking, but if you dont have those , I bet installing those will bring you down 20-30 F....
I have already run my car with a practically brand new 455 in Oklahoma summer heat WITHOUT my original x panels, lower baffles or rubber fillers (to be installed after I get it painted) without any cooling problems whatsoever.
It's my opinion that if you have solved your cooling problem, the added benefit from those factory fixes is not all that great and should not make the difference between boiling over and not.
2012 Mustang Boss 302 #1918, Competition Orange. FGF replacement 2006 Mustang V6 Pony, Vista Blue. Factory ordered. 2019 BMW X3 (Titled to the wife, but I'm always driving it for her. So I'm claiming it) Old projects, gone but not forgotten: 1967 FB 400, original CA car. After 22 years of work, trashed by the guy who was supposed to paint it. I had to sell it. 1980 Turbo Trans Am 1970 Mustang fastback, 351C 4Bbl, auto 1988 Mustang GT, 5 speed 1983 F-150 4x4, built 302 1994 Chevy K2500 HD 4x4, 454 TBI
