you have the same problem most rods do, the fan is too low,the hot water enters the radiator at the top,,,if your running a vee belt system and not a serpintime belt,,,there is a fix to run your mech fan,,,1 build a custom shroud,,or this is the best,,,find a 1960 dodge truck 318 poly,,ive heard some motor homes also use this,,they have a special timing chain/water pump cover,,,it raises the water pump up higher then normal,,it would put it in the middle or higher on your radiator,,,or get a street rod electric fan with built in shroud use it on the engine side puller,,much better then a pusher fan,,,some fans such as the cooling componets fans,,require a lot of amperage,,