Is there a low profile water pump for a 360?

I would run a shroud regardless. I cannot figure out why you are wanting to do this the hard way? You have plenty of cooling system. You don't need another radiator. That radiator you have is better than probably over 75% of the radiators in cars on this forum. All you need is air flow. Put a GOOD electric fan on it and be DONE. In the time you've discussed this on TWO threads now, your car could be fixed and you could be enjoying it.