1995 Astro Sputter

I recently had to replace my fuel pump. At the same time, I replaced the fuel filter, distributer cap, rotor and coil wire. Now, the van runs okay, but when I hit an incline, it hesitates kind of like it did when my fuel injectors were dirty. Injector cleaner worked when they were dirty before, but not this time, and I'm not smelling the rotten egg smell in the exhaust either.

I suspect one of a few things:

Bad new fuel pump, not enough volume under load

Bad spark plug(s)

Transmission (has had hard shifting for a while now)

A friend commented that it sounded like it was missing a piston when the symptoms occured.

Any ideas?

Thanks!

Perhaps a clogged convertor?

What would be a good way to check for that possibility?