I can't tell, from pictures, but it seems that the fins on a heater core are just that -- fins. Am I right in assuming they only increase the surface area to dissipate heat, and don't carry any water within them? I'm referring specifically to the Chevette heater core, which can be had for $17 at Autozone.
I started thinking about this because it's just slightly too large for my case; finding a smaller, low-priced heater core hasn't produced any results. I'm wondering if it would be possible to just trim the fins on the heatercore to reduce it's foot print... ? Anyone else have any thoughts on this?