DO NOT PAY EXTRA FOR A B&M COOLER. THEY BUY THEIR COOLERS FROM LONG, AND PUT IT IN A B&M BOX.

I can't say this enough, after paying over $100 for a cooler I could have had for less.

I did a writeup about installing one on my MGM, but all the pictures got lost in the infamous site crash of 2017.
I should probably repost those.
Anyway, this is what you want:
https://www.amazon.com/Long-Tru-Cool-Transmission-Cooler-4590/dp/B005XZX8RY

This is just the first one I found in a quick search, but Long Coolers make much larger oil coolers than this, you just have to find them. I've seen them on small power equipment like forklifts an skid-steers. It's really worth looking into.
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2007 Grand Marquis LS: 5.4 swap, 9.9:1 compression ratio, Comp XE268s, NPI pistons, PI heads ported by me, Accufab upper plenum, 75mm DBW throttle body, Factory PI intake with Chinese spacers, CVPI dual exhaust, CVPI torque converter, CVPI air-box and zip tube, J-Mod, 3.55 gears, FMS Trac-Loc differential
17" Dorman CVPI steelies, BFG Comp T/A 255/45 R17s