i6's in American cars were pretty rare by this time. It's not uncommon for American manufactures to offer engines of this sort in different engine configs though. Chrysler Powertech came in V6 and V8 config, Ford Modular comes in V8 and V10, etc... The i6 at this point isn't strictly unrealistic, but a V6 would be a better choice. All 3 of the big three had V6 engines as the base US spec config by this point. Personally I'd love to see a diesel I block for the platform. Having only a single diesel in a commercial platform like this is odd and an i block would add a lot more variety than a second V block diesel. If we include Brazilian versions all of the big 3's pickups came with an i6 diesel option. Much of the roster needs more diesel engine options.