Transmission cooler question.

That cooler should be plenty big enough and then some. Check the fittings on it before plumbing. Box says 6AN fittings and I am pretty sure you need 8AN's. It appears that you can change them on the cooler. I'm doing a 46RH swap into an 88 D100 pickup with a 5.9 Magnum and keeping the fuel injection. I run my 3/8 lines down the drivers side frame rail, using steel braid flex hoses from the trans fittings over to the hard lines. Then I use bulkhead fittings at the radiator support like @Icetech did above. It gets the lines out of the way of the exhaust, starter, etc. I just got my 46RH back from the transmission shop. The decades of experience builder told me to run the stacked plate cooler as a stand-alone and don't go thru the cooler in the radiator at all.