Since I am installing an aluminum catch tank well above the engine, am I correct in assuming that I can just have the radiator made without any expansion tanks on the radiator?  
------------------------------

Hi Paul,

You can't eliminate the tanks, but you can make them smaller.  On my first rad, I had 2.5" tanks, but that was because the oil coolers needed that much space to fit inside the tanks.  On the new rad (without oil coolers), I'm cutting the tanks down to 1", which is the minimum that Howe Radiator sells. That one change takes 3" off the length of my radiator. You might be able to go a little smaller than 1", but I'm not sure what the limit is.  You have to have enough tank to allow enough coolant flow.

Rusty (reaching escape velocity from Miami)