Guys you have to put everything into perspective, there are three different alloys here with three different expansion rates, an aluminum head, cast iron exhaust manifold, and a steel bolt. Something has to give, most times it is the steel bolt that is the weak link( which is believe it or not the cheapest part to replace) then the manifold, then the head.
This is a problem with the Hemi, LS engines, Duromax and the Ford modular engines, and Powerstroke, basically engines with aluminum heads and cast iron manifolds. The Ford trucks I would say would be the ones you will use the most foul language on, at least in the ones I have worked on.
With the Dodge Ram trucks, if your truck has less than 100,000 miles an 7 years old or less it should be covered under the factory emission warrenty. My 09 Ram Hemi was covered, my 16 Ram was a diesel no problems, and my 22 Ram Hemi only has 8000 miles on it. My 12 Challenger Hemi I put long tube headers on it in 2014 no problems yet.
All small blocks Mopar came with 5/16 bolts which are smaller than 8mm bolts by 2 1/2 thousands. The reason they didn't snap under expansion was cast iron head and manifold, similar expansion rates.