I have a small block 427 (stroked 351W) and have issues with overheating in city driving. I have tried using the additives like water wetter but no help. I swapped out the FF supplied fan with a higher CFM (3200 CFM supposedly) but no help and I even added the fan shroud from Mike Everson I think... might have been a different vendor. Anyway, anybody else having a similar issue? is the FFR radiator just not sufficient for my small block 427. Anybody look at a custom radiator from Ron Davis? (expensive) Let me know what you know... help