jinkl
those water to air cooler have different core
some quote from
Air to Water Intercooler
Some Water to Air Intercoolers that you can buy online do not contain true water to air cores. 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.
Of course the kit I looking at mostly come with pump
it just the size concern only
need to get the right size only