re: Ford Eco-boost 3.5 ltr

The earlier ones had some issues with the PVC system, timing, cam rattles, and carbon build up. They seem to have corrected most of that with the more recent 3.5L turbo motors to some extent. Same with the 2.7L. You should know that neither motor gets particularly good fuel economy over a V8. The smaller displacement turbo configuration is not to improve fuel economy over V8s - it's to reduce emissions. Keep that in mind if Ford wants to charge you a lot of extra cash for the 3.5L turbo motor.

The Ford 5.0L has recently gotten cylinder deactivation. It's the first version of it from Ford and nobody really knows how they'll last long term. The older 5.0's from 2019 or so have been pretty good, but those don't have the different cams with zero lift to shut down cylinders. Ford doesn't really do elaborate valve timing all that well, so I would wait a few more years for the 5.0L with the new heads to prove itself.

If you get the Ecoboost, your problem with Ford will more likely be with the 10 speed transmission that Ford pairs with all of them. That and with the multitude of sketchy vendor-sourced parts that Ford is scraping together to build these trucks since the pandemic. Ford is having major issues with recalls across the board. The likelihood of obtaining a lemon is very high with them right now.