just rebuilt runs bad

RUN A BACKYARD "cylinder balance test."

Pull the dist boots up off the dist. so you can get a probe in there, and/ or stick some small nails/ brads down into all of the plug wire towers, right beside the wires

Get it running at the lowest decent idle you can

Using a grounded probe, ground each plug one at a time. Do NOT try this by "pulling plug wires." The resulting high voltage will crossfire, confusing the results, and can "kill" modern electronic igntion systems

This should QUICKLY tell you what cylinder(s) are not doing "something."

Try timing it with a vacuum gauge, simple tune the dist for highest vacuum reading at the lowest idle you can manage.

Once you have done these two things, you should be able to tell a little more.

what do the plugs look like?

Depending on the "balance test," don't be afraid to check resistance/ continuity of plug wires, or to check spark at the plug end of a dead cylinder(s)

I think, it's time for a second set of eyes. Take a step back. Get a couple of buddies over there that are good with engines.