I have a 6cyl 70 chevelle which I am changing to a 454 BB. My core support top rail has 3 bolts in it as opposed to 4 and a small opng for air flow to the small radiator.
Do I need to change out the core support to accomodate the larger radiator and anything else that might be different ? If so, where is the best place to order one ? Thanx :confused:

John