Mine originally pointed up and to the side and still had exhibited the richness problem, I went to straight up on the deflector because at that angle I only get exhaust on a portion of the horizontal stab instead of the wing and the boom and the horizontal stab.

So far I have had no heat problems, not to say that you don't but I always set my engines up slightly rich and test them in vertical attitude before I fly them.

How old is your .75? what prop are you running?