Is there a differance between the 2? It seems the 2008 6.4 had more stopping power than my 6.2. Did they beef up the brakes in the diesel vs the gasser 6.2? Did I miss an option for better brakes when ordering?

 

The brakes themselves are probably the same. The difference is that since gas engines generate intake manifold vacuum they generally come with vacuum boost brakes. Diesels have no vacuum to speak of, so the use hydroboost brakes with the power steering pump supplying the pressure. Hydroboost brakes have the potential for much more braking power. On the 6.7 Diesels there is an engine driven vacuum pump, and on some models this is used to run vacuum boost brakes, while other models use hydroboost. I'm not sure if all 6.4's are hydroboost or not. In the past the only way to get hydroboost brakes on a gas engine was to order a dually, but I think that went away with the 2011's.

 

Starting in MY2012 the Diesel SRW trucks with the 6.7 will have vacuum boost brakes as well.