I'm currently looking at radiators for my buggy and I'd really like to have one I can slip down between my frame rails so I can lower the hood line. One of the things I've stumbled on is dual pass vs. single pass. The way I understand it a dual pass rad is the same thing as a single pass except it uses half the radiator to put coolant one way and half the radiator to push coolant the other way as opposed to a single pass which uses the entire radiator to push coolant one way. My understanding of heat transfer is that it's basically a function of time, and that the surface area of a dual pass would be the same as a single pass. However, the volume you can force into a dual pass radiator would be half of a single pass and the velocity would be doubled, basically rendering them two executions that are nearly equal in cooling capacity. Is this correct? Do I understand dual pass radiators correctly or am I off? My stock rad should be 31x19 and I've never ever had any problems with it going over the thermostat temp (210). Obviously it's a brass copper piece and I'm looking at aluminum stuff. If I ran a 180 'stat, seperate trans cooler and oil cooler could I get away with running a 26x19 or even a 24x19 aluminum piece? Single pass or double pass? Thanks for any input. My only other option would be to lean the radiator way back and that would screw up my plans for a 90 degree approach angle since I'd have to move the bottom of it out to the front of the frame.