Just finished installing this unit (Part No. 677) and thought I would dump some pics and one or 2 pieces of useful info.

The first being that the mitsi has 5/16th oil lines and the new cooler has 3/8th!! so you need to get
the brass reducers from Pertek or autoBahn or SuperCheap. Pertek are the cheapest at about $5.
AutoBahn were $7.99.

So when fitting I just cut the Mitsi return pipe from the radiator at a point that gave me enough 5/16" hose length to accommodate the brass reducer, attached the 3/8" Hose (inlet hose to the new cooler) to the other end.....then plugged the return from the Davies Craig Cooler into the return pipe that goes up to the gear box.
(I took pics but it seems I don't have permission to upload them)

The picture on the instruction sheet is a little confusing because it looks like you have
to push the plastic cooler holders in from the back, but the text says different. So they are pushed through from the front. Easy as.

Hi and welcome to AMC. You need to sign up to a photo sharing site like photobucket etc and upload the pics there and then link the direct URL here between and tags.

I have been tempted to fit a trans oil cooler to my 380 but I've never been completely convinced to do it. Where did you mount the oil cooler? Have you noticed any difference in the car with after having fitted it?

I fitted a transmission cooler a few months ago. Accidentally bought one that was a little too big, but fitted it anyway. While driving I don't notice really any difference at all. It's more for peace of mind knowing that the transmission won't struggle in the summer heat. Also handy if you tow a lot.
Before the cooler was fitted, the return line was actually almost hot to the touch, but now I can hold on to the return line as long as I want, so it's definitely cooling the fluid down.

I installed the largest Craig Davies cooler with the brass reducers about 7 years ago. Has never given any problems.

Maybe this might be the next thing on my to do list. Sounds straight forward to fit. I did read though you had to make sure that it wasn't getting the fluid to cool as that causes problems as well, is that correct or not?

You can buy coolers with 5/16th you know, just not as common. I have one in my 380 & TL Magna