[gassman_67]

Originally Posted by Scarebird

I started this morning with the task - clear eyed and open minded. Pulled off the driver's side wires and then went to pull off the passenger side when I noticed this:

https://youtu.be/H8Qx8-C_ZAI

WTF? Is the cap loose? I removed the remaining wires then the cap.

Distributor still moved. Mnnh.

I noted the middle bowl moved while the lower housing remained secure. Pulling the dizzy revealed all 4 upper bolts (red arrow) were loose enough to allow slippage. No lock washers nor locking fluid evident. Green arrow holds upper bowl.



Thanks Edelbrock

Pulled the shaft and removed the screws one at a time, adding a drop of Locktite and resecured. Reassembled the distributor, reinstalled, set timing and road testing shows that this was most likely the issue.

62posbonny: tune map I am using is #2019; pretty mild. Will examine advance curves and fuel more in the future as I am sure this can run much smoother.

I wonder if there is a group that does this with Pontiac V8's only?

Searching the web found me your post. I have a 461 Kauffman, 310 heads and pro flo 4. I also noticed when setting the base timing, it too would bounce around when using a timing light. Then I saw you had found loose hardware inside the distributor, did this end up solving your issue? Curious what timing settings you have. I'm at 17.25 base, starting @1200. 36 max at 3000 rpm and 10 degrees of vacuum advance.