I fitted a plastic, truck cooling fan from super cheap after taking my radiator down to the local radiator shop for a complete clean and flush. I got it pressure tested as well and a few small leaks repaired. I then fitted a new thermo switch as this is good insurance. New anti-freeze and now the whole system is perfect. Oh and one more thing, take your heater core to the radiator shop with your main radiator, these frequently clog up and cause problems
If you have or can find one of the earlier sprint radiators with the copper end tanks, you can have it rebuilt with a better 3 layer core. We got one built for our track sprint for around $350-400. Apparently 30/40% more cooling efficiency.
Best option would be a custom aluminium radiator but would be quite expensive, and probably unnecessary for most applications.