Samsdad,
Don't worry about it! I havee not built a 4* but have built, bashed, and scratched a couple hundred models. The verticle displacement won't have a significant effect on flight. It may have a tiny effect on fuel draw due to the tank height relative to the spray bar. I interpreted your post to mean that the mount is rotated on the firewall compared to where it "should be." This is something that I do all the time to get the muffler where I want it to be.
Chuck