So chatting with my Dad today, and he finally wants to retire next summer from the sounds of it.

He said he wanted to travel the country (U.S.) for a couple years with a trailer hitting every state in the union, I doubt he wants to take the rig on the Hawaii stop lol.

So I had the thought to find, and build whatever needs into the Ex, a V10 for his retirement pleasures.

So just going by a 7-8k TT, and hitting every continental state, I figure oil and trans cooler upgrades, lift not needed, decent all terrain tires on 18's and the stock 3.73 gears should be decent (but upgrading the ratio could make sense as half the country is not flat). Most likely if I cannot find a decent milage one I will swap out trans and motor for new. I don't see the need for a diesel for him as his towing will be so light, unless I run across a 7.3 that wows me.

Any thoughts from our cross country driving members on things I need/should do to make his first couple years in retirement adventures less problematic with an Ex if I can find a decent one in time?

 

I think that you will be fine with the factory oil cooler, I have never read of anyone having an issue with oil temps on these 6.8s, internal leaks are always a possibility but fairly rare.
Trans cooler upgrade to a 6.0 cooler is a good move that will keep the 4R100 running much cooler than stock in all conditions. With my Dorman 32 row 6.0 cooler my trans runs about 20* cooler while towing heavy than it did all stock.
Even with a 7-8K TT I would strongly suggest a 4.30 gear ratio to make the towing more enjoyable and efficient, my change from 3.73s to 4.88s increased my towing MPG 20% and it enjoyed much better performance both towing and unloaded.
All terrain tires ONLY if he will be doing significant offroading, otherwise I think a good highway tread tire would be my choice for better mileage and quieter operation. I am on a set of Nitto Dura Grapplers that are the quietest truck tire that I've ever used and they are wearing great. If upgrading to 18"s be aware of the tire size increase over stock and how that will effectively change the gear ratio, remember the 6.8 does best with a 4.30 to 4.56 effective ratio if doing any serious towing.
I also strongly recommend some custom tunes from 5Star Tuning, the trans shift strategy upgrades are well worth it for improved towing performance.
Be sure to use a very high quality WD hitch with built-in sway control.
I have logged over 40K towing miles with our V-10 EX, the first 15K with a 9.5K TH on the hitch and the balance with the 11/12K TT in the mirrors and I have not regretted my choice of the gasser a single time, uncomplicated and very reliable with ample power and torque to handle our towing needs.

 

I have doubts on the factory oil coolers.

Towing an empty 12' Uhaul trailer from the Uhaul place 16 miles to my Mom's house on the western Appalachian side of TN, the 4R100 overheated in the Expedition and started leaking out the front shaft seal (leaking out the bell housing, I found out is a common problem without a better trans cooler when I looked into it).

The Expi had about 80k miles at that time, I was pretty annoyed to say the least. So with that as a past experience, I don't mind adding a second cooler to trans lines to make sure they don't spaz when doing a lot of mountain driving.

Appreciate the input, this is a maybe idea as a retirement present.

I am sure his 2017 Z71 1500 would probably be fine, just thought I might give them some more room and power to make the planned 2 year sight seeing trip more comfy for them and the dog.

And it would give Grandpa and Skima a big enough vehicle to take all their grandkids for ice cream .

 

Are you talking about the engine oil cooler here in addition to the trans fluid cooler, because that's what I was thinking, but now not sure?
The engine oil coolers are fine and only cause issues if they leak. The factory trans coolers (there are 2 on '01+ EXs, water to oil in the radiator and air to oil in front of the radiator.) are also pretty OK on these big wagons. I did upgrade to a Dorman 32 row 6.0 trans cooler on mine but that was just to have an upgrade, the factory coolers performed perfectly fine for me over 35K heavy towing miles all over the Eastern states, only got over 200* twice for very short periods. The 6.0 cooler is great and has been keeping the fluid about 20* cooler than the factory one, it is a good towing upgrade but not required.

 

I was actually thinking both engine oil and transmission oil coolers.

I have never had a problem with the 5.4 or 6.8 oil temps, but figured a little extra cooling wouldn't hurt the engines.

But I will upgrade the trans cooler (and have on everything I currently own) since I had the over heating failure that caused a front input shaft seal leak when helping my Mom move. Just the circumstances of when/how it happened leads me to think sufficient/extra cooling is a good idea for the 4R100 trans. Not sure on the exact cooler size differences between an Ex and qn Expi, if there is one. But yes the Expi has an air cooler and the one built into the radiator also.

So just to pick your brain Tom, if I swap to 18" wheels with about 265/70R 18's in mind to get a decent ratio around 4.30/4.56 for his towing for MPG would be what gear swap? 4.88/5.16?

 

I just looked up that tire size and it seems to be only about 32.2" tall, so not much bigger than the stock 31.6". With that tire and 4.56 gears it would have an effective ratio of 4.48. I run a 35" tire and 4.88 gear combo for an effective 4.39 ratio and it pulls our nearly 12K TT pretty well here in the East.
I think that it's safe to say that the EX has a better trans cooling circuit than the Expi. I towed heavy with my stock coolers for over 34K miles without any issues, however the 6.0 cooler upgrade has kept the fluid at least 20* cooler in all situations so far.

I have never seen an auxiliary engine oil cooler added to the 6.8.

 

Appreciate the answer, as that was what I was considering doing to my V10 Ex as well. Having a solid answer, sounds like that is a go for mine and his if I can find one.

Or I build mine and give it to him and look for another one for me.

Either way much obliged, that is the confirmation I was looking for.