Searched and don't see anything back as far as a the beginning of 2007.

I'm considering adding an additional trans cooler (2008 Hemi 2500 4x4 with stock cooler). Both series and parallel should give about the same amount of additional cooling. I'm thinking parallel might be a little bit better because it should flow better and an obstruction in one will still have the other flowing.

Any negative to parallel? Anything I'm not thinking of?

Thanks,

 

Series.

 

If you go parallel, the majority of fluid will simply flow through which ever cooler has the least back pressure.

 

I agree series would be better for cooling. Fluid will just take the "path of least resistance" ie the lower of the 2 radiators, if placed one on top of the other. Go with series for full flow and cooling capability....