... Failing that, it has to be the location of the inlet and outlet on the radiator itself. I can't see it being as efficient as the previous. The original rad still had the fan up tight against it but the outlet was on the opposite side which should yield further cooling surely?

Old rad in place with cooling fan...


New rad in place with cooling fan


Location of inlet & outlet...
New:


Old:

^ You can see where the rad was slightly too large and the top mounting had to be bent to make it fit. Epic fail

Would you agree?