Some Water to Air Intercoolers that you can buy online do not contain true water to air cores. (like this code 3 intercooler)

A true water to air core has water passages that are much smaller than the air passages. This is part of what allows the water to air intercooler to be so small and have such low pressure drop. Some water to air intercoolers that you buy online use an air to air core design where the air passages for ambient air and intake air are the same size, with an enormous loss of efficiency.

Now I have no idea if the Spearco cores are like this, but since Spearco has a listing for air cores and liquid cores I would have to assume there is a difference. Again, the C3 IC used air to air cores and advertised them as liquid cores.