I had a veeeeeery unusual o'heating problem with my 440 many years ago. Under certain coinditions, usually a high rpm romp through the gears, temp would climb until it boiled. If driven at moderate speeds, no problem. The problem was the flexible, corrugated, top I had used. When I replaced that hose with a plain sided hose, never had the problem again.....
I suspect the corrugated hose was aerating the coolant....& air bubbles are poor heat conductors.
I suspect the corrugated hose was aerating the coolant....& air bubbles are poor heat conductors.















