Well, it's cracked. How bad is it?

Better off with a flat screwdriver with good sharp edges right up against the leftover tube section edges and tap that piece up and out, because a pushrod is rounded on the end and may just jamb in the old tube spreading the block metal even more.
And yes, that probably is the end of the old one you see, because those holes are not stepped.

Oops, I said I'd shut up. :D