You're doing almost the exact same upgrades that we did in the previous year-and-a-half...stereo (pioneer 8400NEX) ...mirrors (stock ford towing) ...wiring...etc.
The sportsmobile forum is a wealth of information for these vans =
https://www.sportsmobileforum.com/forums/ = both for the van side and the engine side.
We also upgraded from a CTS2 to a CTS3...you may need to upgrade the firmware and call tech support for the CTS3.
For tuning, get a SCT X4...available to buy with tunes from these tuners = gearhead or 5-star or DP.
If fluids + filters + etc. are maintained according to the manufacturer, then the engine will last a long time.
There are some parts that should be upgraded - EGR cooler + STC + etc.
Are you planning to tow on flat land or hills or mountains?
Plan to upgrade the transmission cooler to a Tru-cool max =
https://www.trucool.com/products/tru-cool-max or Derale =
https://derale.com/product-footer/fluid-coolers/hi-flow-fluid-coolers
The stock air filter should be sufficient for your needs.
Might need to upgrade the turbo to keep EGT's lower?
I think we ran the EGT wiring for the CTS through a rubber grommet in the drivers firewall
Instead of a blue spring, consider a custom regulated return for the fuel system. not much more work for a lot more reliability.
Consider upgrading the vacuum brakes to hydraulic brakes...would recommend upgrading the steering cooler at the same time.
Look at these for adding convex mirrors to the tow mirrors =
http://cbetr.com/
There's a lot more to detail, but upgrade a bit at a time.
I would love to have a coil-over suspension instead of leaf spring!!
Some links to help understand the issues and solutions for the 6.0L. I prefer to find the source rather than trust internet stories.
Having problems with your Ford 6.0 Powerstroke diesel? This in depth article highlights the major problem areas and helps you find solutions to keep your truck running great.
www.littlepowershop.com
How reliable is Ford's 6.0 Powerstroke? Learn about common problems with the turbo, EGR cooler, oil cooler, HPOP, FICM, and more.
dieseliq.com
9 Most Common 6.0L Powerstroke problems and how to fix them. The most common issue found on 6.0l Powerstroke trucks is...
dieselresource.com
Common problems with the 6.0L Power Stroke diesel, including clogged EGR valves, sticking injectors, blown head gaskets, and other documented failures. Includes solutions to these problems, advice on preventing them, and how to increase the reliability of the 6.0L Power Stroke.
www.powerstrokehub.com
If you would like more information or assistance in regards to this, we are offering a tech support line to help you through your 6.0 issues for a fee. Please call 970-541-0629 to schedule your phone…
www.btdaa.com
Common problems and suggested solutions found on Ford 6.0L Powerstroke diesel engine.
www.expertswrite.net