The 6.5 is pretty much the same block and heads assembly as the 6.5L engine. There are only a few differences, that being bore size, different rear main seal, and heavier castings. Overall it's a stronger engine but it's built on the same platform as the 6.2 so it should fit no problem.
I think there are some differences in the vacuum pump location and maybe some other external stuff but it's been a while for me so I can't quite remember. H&H can surely help you with this stuff though.