I am cross posting from the van forum, attempting to find an answer.

I own an a 99 E-350 7.3L with 180K miles.
About 5K miles after purchase, my OD light and transmission shifting started acting intermittently on a long drive out of West Texas terrain. I believe it was a heat problem.

The E40D was replaced with 4R100. In retrospect, there are probably tougher transmissions, and I wondered about aftermarket or adapting a Torqtrak, but at the time I needed a transmission and the shop recommended the 4R100 as an upgrade to E40D.

That said I really want to address heat. I am adding a trans temp guage, and I would like to address cooling. I thought about a radiator core swap to get the fluid to ATF heat exchange improvement, but it is probably overkill. Another option is an upgrade to the F-Series air to ATF cooler.

I feel like I have read 1/16 of the Ford/Diesel encyclopedia in the last 6 weeks. I have seen lots of great ideas, but can't always put my finger on them.

I saw a great thread talking about the F-Series ATF cooler being adapted to an E-series van. The poster had pics of the mount up in front of the radiator, etc. Now I am trying to find the pic and the part number, and I cant!

Yes, I searched, but those are some darn common keywords.