Has anyone ever measured their distributor end play? I have a distributor off (as far as I know) a late '60s 230. It has .105" end play. There is no spec for this as far as I can find, however it seems like most people recommend less that .010 for cast housings and roughly .010-.020 for aluminum, due to expansion. I'm gutting my distributor to convert to a Chrysler pickup and reluctor to send a signal to a GM HEI all controlled by Megasquirt 2. While I'm there I'm cleaning everything up and trying to tighten up the loose tolerance. I also noticed there is no thrust washer between the gear and the housing, seems like most all newer vehicles started having them. I ordered shims and a distributor thrust washer, once they come in I'll see if they will work.

So yeah, has anyone measured their end play?

These distributors pull down. But the shimming you want to do won't hurt a bit.

Good to know! I had wondered how it would effect the distributor since it meets in the front of the cam and to the side. I didn't have my engine nearby to look it over and think a little harder! I will probably still shim it just for piece of mind, while researching all of this I've learned that timing can be changed 1 degree for every 13 thousandths of end play. This is assuming it moves up and down, which it isn't going to be constantly doing. However, they pointed out worn timing chains can slap and cause that effect as well. I know our sixes don't have chains either but if it won't cause me any harm but will give me a little piece of mind, I'll go for it.