How much lower for Auto City Rad to clear?

 i can't remember the measurement, but IIRC, the bottom of the radiator is going to hit the head of the core support bolt anyway, so that will determine how much. As I previously suggested, use a glob of play-doh on top of the radiator cap, then close the hood slowly. I think mine showed about 3/16 clearance.

I had moved my radiator forward about an inch or so, so yours may not be as close, and your radiator may not hit the core support bolt. Enough of us guys have used the Auto City Classic radiator to know fitment is not a major issue, just be aware it is a close fit.

On my 59s aluminum radiator from Auto City Classic, I drilled new holes about 1/2" above the holes that were in the rad side brackets. On the bottom of the rad support, I had to grind a small portion of the core supports flange to ensure adequate clearance for the bottom tank, the amount removed was minimal. As Rich mentioned, Play Doh works great for checking for clearance between the rad cap and hood, I also used it to check for clearance for my air cleaner, piston to valves, and oil pickup screen to bottom of the oil pan.