With or without head spacers/ extra gaskets, a 36X is timed for a two cycle, and like a GH Torp 35, and most of the modern engines, was never intended to try running in a classic Fox or McCoy breaking stunt run (4-2-4). You can have fun using it by setting the needle to a rich two cycle setting, and using a lower pitched prop. It likes a Taipan 11-5 prop that has been trimmed down to 10 1/2 diameter.
It has better cooling than a Fox 35, and by comparison to that one, starts more readily "hot" than the stunt motor does (though still not really at all well enough for higher level AMA CL Combat competition back in its own day).
.