The Allen key is one of the smaller sizes.You may have to fiddle a little to get it in the right spot.That can is used on many different Ford applications requiring different timing specs which is why its adjustable.

  

just tried it with vacuum disconnected. may have other issues. feels like surging. tried a different carb also. wonder if the cam is causing some of this. guess i need to put a tach in it and verify rpms. tried sticking a allen wrench in the advance but felt nothing to turn.

Kenny  Onalaska, Texas

You have too much total advance.That will give you surging at high speed.The vacuum advance should be adjustable through the hose barb with an allen key.You should be looking for around 42-44 total including vacuum adavance.This means adjusting the vacuum can so it gives about 8 degrees maximum.You should be aiming for all advance in by about 2500 to 3000 rpm max.I purchased a light spring kit from Mr Gasket 925D part #.About $6.00.Works well.I have my timing at 10 initial with 26 (13L on the  distributoer cam assembly) plus vacuum limited to 8.No problems. 

  

I have 12 initial 38 total without the vacuum advance hooked up. I used my mitivac on the vacuum advance. I seem to be getting around 25 degrees with 15 vacuum. With the vacuum line hooked up to ported vacuum I end up with about 50 degrees timing when I speed the motor up.. I think this is causing my surging at cruising speed. My vacuum advace appears to be non adjustable through the hose barb. How do I limit the vacuum advance and how much do I want. It does not have a stock camshaft. Its a new dist. with light springs so the mechanical comes in pretty quick.

Kenny  Onalaska, Texas