I recently switched the vacuum on the distributor over to the carb vacuum, to retard the timing a little because it was pinging and having pre ignition.

 Now, it runs pretty smooth even at a lower idle. But its missing some pick up and hard to start. I want to advance the timing a degree or two. I know I need to turn the distributor counterclockwi se to advance it. Its been so long since I did i though I dont remember what size wrench to use. Someone here said in another thread 17 mm, I read somewhere else 13 mm. In chiltons it says 78 with 2.3 its a screw. Im pretty sure its a bolt but I might be thinking of my old 74`s I had before this one.

 Anyone know for sure 2.3 1978. I want to get a distributor wrench if I can find one the right size. Autozone has them but not in metric. Just 9/16 and half inch. I think I remember using a spark plug wrench one time, that may have been on an older one.

 I can try it, I have 16mm and 18 wouldnt you know it. Guess il go buy a 17mm. It looks pretty hard to get to in mine. I dont remember it being too hard but that was probably on the 74s I had before.

 Thanks for reassuring its 17mm. Wonder if 11/16 might fit it?

 What about one of these

Socket and extension.
The PCV valve hose will need to get pushed aside some to get it on.