I run a stock HEI with the 350 in the truck, and have been chasing down a low rpm part throttle vibration.

When I was in there doing a advance spring swap, I found the magnetic pickup ring very loose and not screwed down tight tight. Is this a possibility that this could be a source of my vibrations?

Does this need to be centered correctly, clearences etc? I did a search and did not find what I was looking for :)

the pick up is held in place by a snap ring on the top of the upper dist bushing. the vacuum advance locates it. if the vacuum advance is in place it should have little or no play

Thank you sir, I will dig into it a little more in the morning and post back.

Ok, the ring does not have any play against the shaft but the 3 bolts that hold it down were all loose and letting the pickup ring slop around.

I know this is not normal, but can this be a problem if I don't bolt it down the right way?

Three loose bolts and you didn't tighten them down? What is it you're waiting for?

:) No, I did tighten them down, I was just wondering if this has to be aligned or something because they have side to side movement that's all.

Tighten them down and then re set the timing.

YES, you do need to center the outer reluctor with the center one. That "ring" has 8 projections, with tips, that align with 8 on the inner reluctor as the shaft/inner reluctor spins. As the tips align, a pulse is created, and the module reads this, does its thing, makes spark.

IF the distances are not equal, signal strength will suffer for some cylinders, be higher for others.

Only issue is, you should not use a steel feeler gage to set the distance/center, but a brass one, more preferably, a plastic one. Once you get the outer ring centered on the inner other one, then, tighten the screws.

Regards,

Milton