One more thing to consider... For every old car I've bought, the first thing I do is pull the radiator and take it to a local rad shop and have them disassemble, rod out, reassemble, and pressure test. So far every radiator has had some blockage, usually from 25% - 40%. It costs about $50 typically and it eliminates a potential problem.
You can also get a brand new 3 core for about $100...I've got one in mine because when mine started to run a little hot, I couldn't find the blockage anywhere, nor could we flush it out.
www.hannawoodworks.com
