Imperative, I agree about not changing things the manufacturer did without good reason, although I guess putting an A/C into an old car which was built before automotive air cons were invented, is perhaps a good reason to re-evaluate the effectiveness of the original cooling system arrangement. That was the restorer's reasoning for increasing the size of the waterpump impeller. The condenser was mounted in front of the radiator with an electric fan in front of that. With it set up like that the engine was boiling in about 15 minutes in the workshop. Today the condenser and electric fan were removed and the original fan was mounted behind the radiator again, before it was taken for a test run out on the road. It didn't miss a beat and the temperature gauge, assuming it's reading correctly, sat on 170 degrees F. It would appear the condenser is probably causing the overheating, as it covers a large proportion of the radiator ( see attached photo ) but if we don't mount it there, the question is, where can we mount it ?