[ChuckS]

My concern for either of the Fords would be if the 6.0 has been bullet proofed. If not I’d pass ...

Here’s a bit of history on the 2005 Duramax....

2004 - 2006 GMC SIERRA, CHEVROLET SILVERADO
For 2004, the LLY was introduced alongside the LB7 before replacing it indefinitely. 2004 - 2006 models often suffered from overheating issues while towing. The aftermarket has responded with a variety of fixes, though buyers should be aware of the issues when searching. For 2006, the LLY underwent many changes, including a stronger cylinder head design, newly designed fuel injectors, a new VVT turbocharger, reduced engine noise, and performance was boosted to 310 hp and 605 lb-ft. For 2004 models, the 5 speed Allison automatic was available, while the Allison 1000 was upgraded to a 6 speed unit in 2005 (the 6 speed version being more desirable).

And yes.... I’m a Duramax fan. The newer Ford diesels seem good and the Cummins of course is good as well.