I can't agree more.

I use a 123 distributor in my W108 and my Fiat 500 (the old two-banger), about to get one for another old car.

Aside from what was put down in the excellent post above, know that the 123 is essentially putting a brand new distributor in your car, which in most 40 year old cars, is probably a good thing. The original distributor is likely worn (shaft wobble, advance randomness, etc), and getting it rebuilt negates the higher price of the 123 system.

Another benefit of going to a truly modern ignition is the ability to get rid of the voltage-reducing ballast resistors and getting full voltage to the coil.

Good luck!

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Looking for Early 108 windshield surround wood in decent-to-good condition.

I cant seem to find this in the archives, perhaps Im seaching it wrong.
I have been looking through this though...

PerTronix (Hall Effect) Ignition for Mercedes-Benz Pontons © www.mbzponton.org

I would love to drop in a 123 but I may end up doing an engine swap, (smoking good, compression test this weekend) in the near future so for now a Pertronix will have to do.

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1969 w108 280s

That's the one I was referring to - worked for me.

Since a number of posters brought up unstable advance from the mechanical weights, how bad is it in practice? Under a timing light the marks are pretty stable at 1000-4000 rpm.

Just curious how much of an issue this is. My car has 88000 miles, but the distributor has been replaced at some point.

When you say the advance is stable at 1000-4000 rpm, do you mean that you see no change in advance? If so you do have a problem. It can be corrected by freeing up the centrifugal advance weights.

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

No, sorry for the poor wording. I mean that at various steady rpm between 1-4k the advance is also steady at a value between 10-37 degrees. It does not appear to bounce around. I have cleaned and lubricated the top portion of the distributor, but that does not account for wear and tear.

Thread jacking:

I've been searching for a Pertronix unit for the 190 W110, I haven't come across many references to my distributor number.

121.924 block/121.010 head (W110 block, Ponton head) and my distributor is VJUR 4 BR 27 T. The link above to installing Pertronix and the application guide has a similar distributor (VJU 4 BR 27).

Dunno if anyone here has already tested which distributors are identical, I've found many references to other distributor part numbers but never that one. For reference: Pertronix for distributor VJR 4 BR 24 T

I've emailed Pertronix and I have yet to get a reply. I'll probably call them tomorrow and bug em.

Coming back around here...

Pertronix in hand.
For those of you running a stock Bosch coil with Pertronix.

Did you bypass the resistor and go straight to the + and - of your coil?

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1969 w108 280s