The 1964-65 911 Cast Iron Distributor
This Bosch Distributor is the first one in the 911 series. The tag reads 0231.121.006. This 1964-65 911 distributor is a cast iron distributor with a Black identification tag and a 15-degree max distributor advance, which is 30 degrees engine advance.

This is a clockwise spinning distributor. Weights in the distributor spin out as the revs increase and advance the timing. The weights do the job by sliding on a plate, this can have problems. One of the problems is sticking weights. This can be why this distributor can hang up and the engine can take a longer time to return to idle.
Rebuilding the 0231.121.006 Distributor
When rebuilding cast iron 0231.121.006 distributor there are a few mistakes to avoid. We have seen many little mistakes that cause big problems. One mistake we see the most is the use of incorrect parts. Like the wrong condenser, wrong springs or wrong sliding plate.
One problem we do not see often, but it has dire consequences, is painting the inside of the distributor. Because the cast iron can rust, some people feel they need to fully paint the distributor. The problem with this is the points get the ground from the distributor body. Paint means the points can’t get a ground and the car will not run.
The sliding plate is another problem area. For many years there was a replacement part on the market. The replacement part touted that it was superior to the original sliding plate because it was made out of silicone rather than Phenolic. The heat from the engine gets into the distributor and curls up the silicone sliding plate. When the plate is curled the weights cannot move freely and it will stop you from getting full advance or troubles returning to idle.
Porsche cross reference number
Porsche made their own part number and did not use the Bosch number 0231.121.006 that is on the black tag. The Porsche part number is 901.602.021.AX. If you have an original distributor in your original car, you have a rare and sought after Porsche!