Mike if you put a corrosion inhibitor in the cooling system it should stop that. The other benefits of that are that it should Lube your pump seals(so it is said) and it will stop the buildup of scale which greatly assists in heat transfer and therefore a more effective cooling system. This is important with the Ford flattie because they are known as "hot" engines. Bearing in mind that the engine is trapped in a box, the air flow entirely comes from the windmill at the front.
I run a 3 5/16" bore (which increases the potential for trouble) but in saying that I have done every thing I can to keep her running within range. I run 180 degree thermostats and a 4 pound cap(I made an adapter to take a Morris Minor cap) The original pressure cap is supposed to relieve at 3.5 pounds (during WWII Ford upgraded their radiator seam laps because they were splitting) Waffle finished
I'll add James's contact details here again. I take no pecuniary benefit from James. He has just treated me like a valued customer.
James Saccoccio
Gotham Auto Parts,LLC
340 Cherry Street
Bedford Hills, NY 10507
sales@gothamautoparts.com
Tel: (718) 878-3699
Fax: (212) 519-790