I'm baffled! MSD distributor will not drop in?

[sixty9cobra]

did you compare the gears? upside down, wrong Dia, wrong rotation?
                       Harry

[Rory428]

I can`t believe that nobody has mentioned this, but did you try rotating the crankshaft while holding the distributor downward? Often I have had a distributor not want to drop down, simply because the dist. gear and oil pump drive were not aligned. Usually turning the damper 1/8th of a turn or less is enough to make everything fall into place. The fact that all your measurements are good, and it didn`t drop into the old engine again makes me think that is all it is. Either that, or perhaps the oil pump drive rod lifted out of the oil pump, and is sitting cockeyed and too high, but pretty unlikely that is the case with 2 different engines.

[fairlaniac]

I can`t believe that nobody has mentioned this, but did you try rotating the crankshaft while holding the distributor downward? Often I have had a distributor not want to drop down, simply because the dist. gear and oil pump drive were not aligned. Usually turning the damper 1/8th of a turn or less is enough to make everything fall into place. The fact that all your measurements are good, and it didn`t drop into the old engine again makes me think that is all it is. Either that, or perhaps the oil pump drive rod lifted out of the oil pump, and is sitting cockeyed and too high, but pretty unlikely that is the case with 2 different engines.

I mentioned turning the crank, last comment in my opening post. Pump drive is in pump.
Thanks!

[HarleyJack17]

It sounds like you are on your game but it can be easy to miss things, especially if you start going down a single road.
Make certain the pump drive is installed in the correct direction...its been done before.
Is the cam in the correct place/torqued? This is a long shot but possible-think you may have eliminated this with the old dizzy.
When it bottoms out is it free-or stuck? I had to clearance a little on my pertronix-again I think you checked this.
Verify the gear is installed at the correct depth on the dizzy- If not the gear will hit the pump drive deck and dizzy not fully seat. I have done this and it was costly.
Is the shaft in the dizzy possibly bent or offset?
Again, I am sure you have checked all this but it may not hurt to make a list and go line by line checking it off.
Find the root problem or it will show up later and likely in a costly way.
You are not the only one that runs into things like this...TRUST ME! 

[Falcon67]

It doesn't look mushroomed but I did run a file around the edge to make sure.

The end of the shaft isn't going below the top surface of the hole to even catch the oil pump drive.

I think if I pull it apart and put the gear on the shaft and drop it in I'll see where my issue lies. I assume if I pull off the collar and the gear the shaft comes out of the body? No other part should unexpectedly fall out I assume?

This is just freaking weird.

thanks,

I keep distributor bodies without gears on the shafts just for similar issues - tweaking the position of the pump shaft to let the real dist. drop in, etc.  If possible, mic or caliper the shaft from the gear down to the end to make sure it's a consistent diameter.  If the shroomed the shaft getting the old one off, it's be hard to get an new gear on anyway. 

[fairlaniac]

Mushroom is the winner! I moved my dial gauge to the very end of the shaft and it was out. Dressed up the end a little @ 3/32" from the end up and it took car of it. It was barely catching the edge of the hole.

Thank you all and I hope others as well as me learned a little something.

[turbohunter]

Thanks for doing the work Doug.
Something else to keep an eye on.