Update
 

I finally got some time to work on this project. After replacing all the rubber hoses, injector seals, and all gaskets and seals in the intake system, it still drains fuel into the intake. I took the advice of duxthe1 and decided to look for a complete fuel distributor in a wrecking yard, and replace it (rather than just replace the plunger seal). I found one today, and did just that. It does not leak into the manifold anymore, but it would not idle either. I adjusted the flapper (not sure exactly what it is called) a little by leaving the center bolt a little loose, and moving the flapper until the idle smoothed out. It idles great now, but it is really boggy, and does not rev up well. It also is very hard to start (cranks for a long time before eventually starting). It was slightly boggy before, but much worse now. Did I get a bad fuel distributor? Should I go back and get a different one and try it? The distributor was from a single cam engine, and mine is dual cam (not sure if that makes a difference). I am not sure where to look for cause of the bogging problem. Anyone have any ideas?

Moving the plate was a bad idea. It needs to be centered perfectly or it can cause other problems. BTDT

Every fuel distributor can be slightly different and the fuel mixture needs to be adjusted after replacing one. This is accomplished by adjusting the 3mm allen inside the "tower" next to the fuel dist.

Replacing the fuel dist with one from the single cam engine isn't advisable. It may run but the twin cam part is designed to flow more fuel. This may be the root of the bogging problem.

Recommend to take the old fuel dist and try to replace the plunger seal. Not much to lose and everything to gain.

Understood, thanks.