I like him at 170, but I think 185 is probably better. Sherdog Fight Finder
lists him at 6'2, so he's not short for 185, and he will still be powerful. Also, 185 has less "technical" wrestlers than at 170, so I think he can compensate with strength and speed.
The thing we don't know much about is his submission defense, though, except for the fact that he got submitted by Koscheck.