What would cause an HEI voltage to jump around? Motor is cutting out around 3200 RPM. Feels like it is running out of fuel. Drives normal when RPMs are dropped again. Fuel system looks good. Just wondering if this would have something to do with it. Thanks for any and all help
.(posted this previously, but apparently it did not work.)

 

Where are you measuring that voltage?
\How is power routed to the distributor?
What is the alternator output when this is happening?

 

That is a highly untrustworthy volt meter. That is the "free with purchase" Harbor Freight meter. It is fine for static voltage readings, but I would not trust it for this kind of testing. HF does have other meters that seem to work well on a budget, I have one. But those freebies are hard to trust. I have a couple of those as well.

Make sure you have the negative lead touching a good ground point like the neg battery post and a good solid contact on the pos lead at the distributor cap connection . If you are using a neg connection on the engine, make sure the battery cable and body strap are clean and tight. Bad grounds cause a LOT of "ignition" issues.

 

If the pole piece/pickup coil in the distributor is failing it could a voltage surge. The common failure mode is that the wires (2) fray where they enter the pickup coil. To test for the symptom described, unplug the vacuum advance and drive it to see if the symptom changes, if no change the pole piece is probably good.