You don't need to pull the head to check for TDC, you can use a piston stop tool that screws into the plug hole. Turn the crank until it hits the tool, make a mark on the damper, then turn it 360 in the opposite direction until it hits the stop and mark the damper again, TDC will be half way between the two marks.
Also a low vacuum reading isn't unusual with a non stock cam, best I can get is 14..

I know people use vacuum to set timing.  It does work to get close.  If a timing light was not available, but a vacuum gauge was, I certainly would do it.  However, that method does not usually end up with the right timing for the engine.  It is more of a get you down the road method.  When trying to solve problems such as these, you want to eliminate all of the uncertainty that you can.  That means a timing light is required.


Lawrenceville, GA

My outfit has the factory cam - so its no thumper (unless its running severely retarded). Even in that state of cam time, best vacuum is a bit more than 10º - more like 18º. If I set it there - with the vacuum disconnected - the additional mechanical advance I have in the distributor would over-advance the engine as the revs go up. So the mechanical advance would need to be restricted to prevent that. This has happened to more than a few "experimenters" when they try to do a set-up purely utilizing a vacuum gauge.

I'm a believer in utilizing live manifold vacuum (not "ported") to operate the vacuum advance. So - I set my initial timing at 10º - and I have the vacuum pot restricted to only adding a maximum of 8º. So when starting the engine, the 10º contributes to a quick "fire", the 8º then quickly adds on and takes the engine to the max vacuum "sweet spot". The sum of my initial and mechanical is 35º and its all in by about 2500 rpm. Springs to do that are available from Mr. Gasket - but in my case, it had to be done by trial and error (no access to a Sun "distributor" machine).
  

 
 Steve Metzger       Tucson, Arizona

He said they used a timing light. If he can read 42 degrees it must be a dial back type. Makes me think about a friend who had a similar reading, he worked on scrubies all his life and when timing the Ford he had the light connected to #5 LOL. About 45 degrees off...

You're right.  And that could be another part of the problem.  Dial back lights are not as accurate as standard lights and can be quite a bit off.


Lawrenceville, GA

It was not a dial back style light. The marks on the damper go up to 50. Just found a receipt in all of dad's paperwork where he ordered a new damper from Mummert. Just don't know if he ever put it on or if its on a shelf somewhere. One more thing to look into.

No stock damper is marked to 50 degrees.  If he got it from Mummert, it may be a Powerbond damper.  That could have more marks than stock.  I've never seen one.


Lawrenceville, GA

Ok, so I verified TDC and the timing marks are right on for TDC. Checked the rotor in dist. and it has no spring back from mechanical advance. Started to take apart to check and have ran into a problem. Even after reading shop manual, I cannot get the breaker plate out. It's almost like there are more screws holding it in that I cannot see. Anyone have any tips or experience with this.

According to my 59 Truck Shop Manual there are only 2 Screws holding the Breaker Plate in Place. Looking at your Picture it looks like it may simply be stuck to the Housing with Corrosion. Have You tried spraying some WD-40 or similar around the Breaker Plate where it sits in the Housing. If there is no spring back from the Cam Assembly it must be pretty Rusty under the Breaker Plate. If this Disributor is in bad Shape once You get it apart the Cardone 30-2808 is a replacement and it easier to Setup because it has the later Vacuum Advance which can be adjusted with Allen Key. The One You have uses spacers and Springs to change the amount of Advance. Its probably easier to work on the Dist. on the Bench. If you set the timing with rotor pointing at #1 on the Cap and TDC on the Balancer  and make a mark where the advance unit is pointing You will have reference when You put it back in. Hard to work on these in the Vehicle because of Location on the Engine. 

  

Doesn't that C-clip have to come off the pivot post?