Exhaust Port Optimizer install problems?

Maybe it's just not my day. I'm having problems with the 1/2mile exhaust kit from Omar's. I tried calling but hey, it is sunday. Anyway looking at the pic below, I marked the EPO with A,black line and C. It only makes sense to me for the EPO to be inserted in the head with A, where my thumb is inside, going into the head. Should the OD of A be cut so that it completely slides in the head, so that black line goe's against the original exhaust gasket sealing surface? If that is correct either mine were not machined enough, or I have to sand them, or the head portion they should slide into. The head is clean, no carbon is keeping them from going in the way I think they should.

If it won't go all the way in then there is a good chance you didn't get the stock gasket out of the head. Just my guess.
Leo

Gasket were out. Came out stuck to oem pipes. I finally said to myself, "Quit fukn around" cleaned the exhaust bore spotless, radiused the outer edge, same for the insert. Slowly worked them in. Done, for now, till they come out for final build.

Sometimes people put an extra gasket in the head then crank the bolts down so tight it expands and gets stuck in there. You take 1 out and think you got it all out...