Slant six distributor drive gear

lowbudget said
The hole that the roll pin goes in to hold gear on dist. shaft. The hole in the gear you purchase has a hole but is not in the right place. With all the reading I've done I still don't know it's purpose but what I do know is it is not for the roll pin. See .org links above for details or factory service manual. I suppose a Chrysler design engineer is laughing his @ss off some where. I guess it might a reference point of where to roll gear to drill the hole in the proper place??????????????????

The OEM service shafts in the 1960s did not have a hole drilled in them. You would use the hole in the distributor gear to create a new hole in the shaft. You need to carefully look at the wear patterns on your existing gear (assuming this is possible) and ensure that the gear is installed centered with respect to them. This guideline should be used in combination with the FSM instructions.

The improper alignment of distributor gears from the factory, from the factory rebuilders and varying dimensions of parts was an industry wide problem. Ford alludes to this in their performance catalog. In case there was a scintilla of doubt about MOPAR escaping this issue, the examination of a NOS factory rebuilt distributor removed it.

EDIT: Do yourself a favor. If you do not have a proper drill press and clamp/jig to hold the distributor shaft in place then take the whole shebang to a local machine shop and have them do it.

WHY?

Because if you drill through the gear and/or shaft at a skewed angle it will mess up your timing. The Nylon gear expands dramatically at operating temps and the misdrilled hole will allow the gear to shift and rock as it operates. The same thing will happen if you mess up the thrust clearance. How can I say this with surety? Because I took the time to pull used distributors in wrecking yards and look at the wear patterns on the teeth of improperly replaced gears.

I have to mention the dual roll pin seen in the slant six dot org logo (factory 1960 drawing). The factory engineers were intelligent enough to know that the rocking of the Nylon gear would be a problem in performance applications. Accurately drilled dual roll pins would solve it.