GM stopped making the 8.1L that you have a few years ago.
Now Ford's new plan with the full sized vans is to only put in V6 - either the 3.5L Ecoboost or the 300 HP 3.7L gas engines and one diesel, a 3.2L inline 6.
The larger vehicles are on the way out. Surprising though is the replacement Ford Transit (made in Europe since the 60's) to be built in Kansas City plant will be 3 heights and 3 lengths so it can be larger yet lighter, and get better mileage. The dual rear wheel Transit will have a 500 cubic foot interior space, while the shortest ones will be about 1/2 that interior volume.
Fred.