Distributor Shaft Play and Remedy

I have recently been converting a 1926 distributor to use a Pertronix ignition.
In doing so I realized that these early distributors did not have  the spring and disc that the 1934 and later distributors used to control shaft play.
With points ignition it is very important there is no play between the shaft and distributor housing so a consistent point gap can be maintained.
As near as I can tell Chevrolet started using a wear disc and spring under the grease cup assembly starting with the 1934 Master and continued using this design up through 1962. This design prevents the shaft from moving side to side in the housing.

Assembly from a 235 distributor

The 1926 distributor is not as deep in the area under the grease cup assembly as the later distributors that use the spring and disc. This means using a shorter spring is required.

1934-62 style

1926 style

The original disc Chevrolet used was a solid disc. It was .312" diameter x .125" thick.
I found a similar nylon disc at my hardware store that will work fine. These are called #6 screw spacers
They have a hole in the center but that is of no concern.

New disc with spring

New disc with spring

The spring I found online is .030"OD x .022" wire x .500" long.

Spring package

Nylon disc package

                                                                

This disc and spring combination works well to keep play out of the shaft.
If converting to Pertronix the shaft play is not as important.

Grease Hole

Disc In Hole

Disc And Spring In Hole