i am trying to replace the heat exchanger on my blueline cobalt machine (i will attach a diagram with the exchanger and its assembly )

what criteria need i be concerned with specific to replacement of the core beyond

-psi max
-heat max
-sizing to fit the assembly case
-ports which can be fitted through the existing front plate hioles

i ask this as the replacement frpom https://shop.truckmountforums.com is over 2k and i can see no reason to pay that as it looks exacctly like the others

and i think has all the same thresholds

am i missing somethiong?