distributor problem - 350 V8

So the small plastic sleeve on the oil pump gear broke, and I replaced it. The issue is that my dist. won't go down all the way, its about 1/2 inch above the intake manifold. Is the sleeve still too far up? What is my problem??

Sometimes it's hard to get the teeth on the distributor and the teeth on the cam to line up perfect so you just have to play with is a little bit more than likely.

It also may not be engaging on the oil pump drive, once you time the distributer with the cam, slowly turn the motor over and hold down on the distributor down and it should fall into place.

This is almost funny.  I say almost because I'm sure it's frustrating for you.  That neoprene sleeve installs from below.  That's probably how you broke the first one?  Pull the oil pan, drop the oil pump, slide that sleeve onto the driveshaft for the oil pump, and then reinstall it. 
 
There are also other factors that can cause your distributor not to be fully seated.  For instance, if you accidentally installed an oil pump driveshaft for a big block chevy then the distributor will never go down as it's about a half inch longer than the small block pump shaft (other than that, they are identical).  Another problem might be a damaged gear on either the camshaft or the distributor.  This however should be obvious if you take a close look.  Seating the distributor can be a little tricky but not as hard as you might think.  Use a long shaft flat head screwdriver to spin the oil pump shaft slightly and try to stab the distributor again.  You may need to do this several times.  NEVER try to spin the motor "without" the distributor being fully seated.  You could damage the gear.  You can't "force" anything with damaging something.  You'll pay for it in the long run. Take the time to figure out your problem first.