I currently have a 2 core radiator in my 74 K5 w/350. I have overheating problems and I heard about the 4 core radiator upgrade. I recently purchased the Big 4 Core Radiator that is made for the 454 engine. I have heard how some of you had to upgrade the upper Radiator support. Does anyone have the part # for that upper support? Or if now part number, does anyone know which vehicle I need to tell the dealer I have to get the right support? Thanks in advance.