I have actually looked at a large car radiator, but I found a transmission cooler that would be much more suited for my needs. It's got 2 individual cooling areas instead of using the entire radiator for one loop. That actually works out pretty well because I have 2 different computers that need to be watercooled. I haven't decided if it would be a good idea to run them both on the same loop, that's going to add a LOT of heat. This requires a lot more thought than my vapochill!!
I doubt that I will be trying the block in aluminum AND copper after 2 days of reading on thermal properties of various substances. My "idea" was just another example of me over-analyzing relatively simple things. I think I have the OPPOSITE of ADD...maybe Attention Surplus Disorder. Once I focus on something, it stays in my mind and I think about it constantly until I think TOO much and make it far more complicated than it really is. :shrug:
Now if I can only figure out how to drill holes in copper that are SMALLER than .25mm.