Honestly man, do it at the same time you do your cam. It's just injectors, a few fuel filters and a tune. You'll already have the injectors off so why not? Get a canned tune set for E85 and a cam, and then get a dyno one later. It'll cost you a $100 more and you won't regret it. E85 is by far the best thing to happen to our sad modding scene. It's awesome.