I'm doing something super similar to that PT. I've taken a RR transmission cooler, made a bracket to fit it between the wings of the CrewCab. It fits in there with a 1/2 inch spacer perfectly. Will locate it towards the top end of the space between the radiator and the radiator support arms.
I'm going to run it as an engine oil cooler, complete with temp sensor.
I've gotten as far as mounting the cooler, procuring the remote line fitting that goes between the filter and block, and all the hose. Now all I need is some fittings and a bung for the sensor and an oil change. Sound simple? I've been cobbling it together for the past year. Now I'm just getting around to actually installing it.
Just another idea for an alternative use of a transmission cooler.
They are notorious leakers in the RR's, so I would suggest some really good fittings instead of hose clamps. We all know how well the hose clamps on the PS reservoir hold in the fluid. :flipoff2: