Don't worry about it. Really. I was 6'2" pre-HRT and very, very muscular. After 3 years of HRT, I've lost 2 inches in height and a lot of mass. I pass just fine... even at 6'2" I did pretty good then as well. There are so many things more important things other than just height and pure physical appearance alone. Trust me. I've met plenty of very passable, fem looking MTFs... but upon a closer look, or when hearing their voice, watching how they move, sit, etc. really miss the mark due to small details. Being accepted as a female requires a lot more work than just pure physical looks.
PS: My SRS surgeon (who is also MTF and pretty well known) is around 6' tall and she gets by just fine too. Really, don't worry about it.