Sorry, I'm late but, based on your posts, both pieces are angled the same, so there is a "constant" gap all around the part? So I can assume you have the axis's "in-line", right?
You used Insert (I'm iffy on Insert) and it didn't work right?
You used Mate, as in "surface" of tapered pin to "surface" of tapered hole, or other means?
Mr. Pickles