I took the radiator out of my 261 and had a rad shop clean it up for about $100 and it works fine. At their suggestion I put an 8 pound cap on it.... and so far so good.
I have the same rad in another vehicle in which I run a 400 HP 355 CID V8 and I took it in and had them rebuild it and add an extra core - for a cost of $400. It keeps my V8 cool - but it still doesn't like rush hour traffic.
