I am pretty sure it has nothing to due with the fuel because I have an O2 sensor and I did not see a lean spot.
I have the Edelbrock heads, so airflow is not a problem, and 5500RPM should be a breeze.
This was only the second time I have spun it up that high while I was watching the tach. The first time (about a month ago) I thought it was just my imagination, so I did not worry about it.
The tach does not fluctuate up and down, it shakes erratically until I shift into 2nd, then it is fine again until it gets near 5000RPM again. I can still feel the engine trying to increase in RPM past the 5000 mark but it is very weak.
I forgot to mention that this happened once before with a different distributor that I tried to refurbish, but the problems started at 3000RPM. Then I got the Mopar Performance dist. and I thought that solved the problem...I guess not.
I am 99% sure it has to due with the electronic ignition. I might borrow my father's coil and see if it makes a difference, since that would be the cheapest route first.