While troubleshooting a stumble at 5000 RPM I found what I think is an uneven wear pattern on the inside contacts of my distributor cap.

Does this look normal?

Looks fine to me. All that means is that the sparks are jumping more on the lower end of the terminal (with reference to the photo) than on the upper end. There's nothing excessive about the terminal erosion in the photo.

I agree, typical wear. All of the posts should look like that, and the edge of the rotor will have some pocking to it. Nothing in that picture to cause a miss.

Turns out my distributor was 180° out of phase. I pulled the oil pump, rotated the drive pin and after fighting with the firing order (one of my books had 5 and 6 reversed!) the engine seems to run fine.

I'm not sure if this was the cause of the miss or not as it seems to be intermittent. Time will tell.

Thanks for replying.

I did that one time on my old VW Bug. Wound up bending pushrods, because I was still able to get it started.

I did that one time on my old VW Bug. Wound up bending pushrods, because I was still able to get it started.

Ouch!

Turns out my distributor was 180° out of phase. I pulled the oil pump, rotated the drive pin and after fighting with the firing order (one of my books had 5 and 6 reversed!) the engine seems to run fine.

I'm not sure if this was the cause of the miss or not as it seems to be intermittent. Time will tell.

Thanks for replying.

Since you rotated the distributor shaft 180 and then realigned all the wires 180 there is no change from a timing standpoint.

Steve

Since you rotated the distributor shaft 180 and then realigned all the wires 180 there is no change from a timing standpoint.

I agree and looks like the problem did not go away. The hunt continues!

I installed an MSD box this afternoon and looks like this fixed the higher RPM stumbing issue. The car pulls harder than it ever has throughout the power-band.

http://www.classiczcars.com/forums/showthread.php?p=339403#post339403

I suspect that some other part of the ignition is marginal and the MSD setup compensates for it. For now I am happy with the results although I did not really find the problem.