1975 Dodge Coronet. Pulled the distributor to replace the vacuum advance pod on it. When I removed dist, I orientated the rotor at exactly 12 o'clock, straight up facing engine block. However after putting in new pod on the bench and reinstalling it, I could only get it to drop it @ either 11:30 or 12:30, not exactly at 12 o clock. I adjusted it and it ran great anyways. What gives? Something I'm missing?

The adjuster moved to a different position relative to the distributor body. There's two slots on it. One on the bolt that goes to the engine, and one on the bolt that holds it to the underside of the distributor itself. If this bolt loosened up a smidge....

OK, I am confused. If the dist drive gear and rotor are orientated on the shaft to each other, how would that affect me being able to drop it back in @ 12 o'clock position?? Even if those slots did get pushed around, it shouldn't cause this effect?

For some reason the new pod has repositioned the movable base plate where its arm attaches. It could be the new pod's arm is a bit longer, or shorter, or you may have got its peg seated into the wrong hole.

Check base timing, and rese if needed to be same advance that you had engine timed to before this project.

Depending on which pod you now have it may have different starting advance vacuum level and or may not give the same amount of advance that your old unit did.

Some of these pods can be adjusted by an Allen wrench inserted into the vacuum orifice and turning it either way until desired advance parameter is achieved.

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

Ok, that makes sense. Thanks guys..

Or the peg doesn't exist and you tightened down the screws and lost your index by 10 degrees....(I farted around with seeing how much a missing peg could mess up the plate position on the dizzy machine...educational, but a good waste of a few hours of moving the pod around... LOL)

I'm quite sure there was a peg and I'm quite sure it went in the original hole that the old advance can arm came out of.

Maybe I need to ask this question this way, when removing the distributor, I thought I had to replace it with the rotor in EXACTLY the same spot it was when I took it out?(in my case the rotor tip was facing 12 o'clock) Or do I just need to get it "close" ? (in this instance the rotor ended up sliding in at 11:30 or 12:30) Is there something I'm missing here?

Anyone??

I would just re-index it at this point if it won't slide in right...

Get the #1 cylinder to TDC (make sure the rocker arms are loose/ can wiggle with a finger, so you are on the right TDC...LOL...and hopefully your damper hasn't slipped and the damper mark is spot on).

Set the damper mark to the desired "static" setting (5 BTDC or whatever you are setting your distributor for).

Install distributor, you will need to "clock" the rotor as the helical gear will move the shaft and rotor a few degrees from where it was pointing... I would set it, install it see how the rotor turns, then pull it and clock it so when you install it the second time is rotates into a position that is close to what you need... rotate the body to adjust...if you can't get it to rotate the proper amount you will have to pull and adjust the bolt on the bottom of the distributor body to give the bracket a bit more room...if you think you are going to do a bit of distributor tuning... I would go to your local tool shop and get one one of the distributor wrenches (or get a harbor freight long handled cheap wrench and have a buddy heat it up with an oxy acet torch and fold it over 90 degrees in a vice....

With that tool, you can make that adjustment without having to pull the distributor to loosen or tighten the bracket bolt...

If you have a 1979+ distributor hold down (ring and clamp style), disregard that advice and just loosen and twist to the index you desire....

Got it !! Thank you very much !!