My buggy runs a rear mounted radiator and it has the stock water pump. The biggest issue that I have had is purging all the air from the heads. After fighting this for years I installed a small ball valve on my thermostat housing to vent steam. Then I put an optional female hose fitting on the valve So if I desire I can connect the garden hose to it and open the valve. This makes it easy to backflush all the rusty crap out of the motor. And be sure all the air is out of the system. of course in the winter I run sierra or one of the other pet safe antifreeze brands auto zone gets it for me on request. It is not cheap to do it right but you will save money in the long run if you go to evco or someplace that sells the appropriate type of hose for this sort of thing. That way you dont end up with a bunch of mickey mouse crap flex hoses and exhaust pipe like I did that sucks, It would more than likely be wise to upsize your radiator because it will lose efficency no longer being in the flow of air. Dont mount it right up against the cab this makes it almost impossible to get adequate air flow. It needs to be as high as possible and mounted if possible horizontally with electric fans pulling the air down through the radiator. And by all means either wire the fans so they run whenever the engine runs or has a thermostat switch that turns the fan on when you reach operating temp. Otherwise you will forget to turn them on and cook the engine. I have seen some heart breakers because this was not done. Also a large scoop on the radiator will increase airflow in high speed situations probably not a benefit at slower speeds. I am sure someone will want to argue with me about something that I have written here but I have built more sand cars than I can remember and learned these lessons thru trial and error. Personally I am a fan of keeping the radiator in its proper place with a foolproff mechanical fan and shroud.But also realize this is not always possible. Good luck. Mombo.
