I recently bought the 57 TBird tach drive distributor.  It has a rebuilt vacuum advance can and looks to be in good shape.  No play detected in the shaft.
What is the best way to test the vacuum advance?
My car is a 55 (I know I need to modify the carb), I have the 55 manual.   Can anyone provide pictures of the 57 manual with the distributor info?

Hello  Hook up a hand held vacuum pump and watch for movement of diaphragm arm.

As mentioned, a hand held vacuum pump.

What you want to do first is pull enough vacuum to have the single breaker plate advance and retract fully (release vacuum) to verify if there is free movement and no binding.

Then hold steady vacuum to ensure the canister is good and holds vacuum.

The main trouble with these (1957-1959) is that the single breaker plates rotates on a series of ball bearings and they can come out of round due to poor DIST grounding and will cause binding.

Let me look for my 57 WSM and will print off the page.

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Even a bit of vacuum hose and suck on it will move it. 

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Thank you for the info.   Are there different springs available for the mechanical advance?   How do I get to the springs, just remove the breaker plate?

Yes, the springs were (are) available as a service part.

The easiest way out of it is to find a good speed shop that has a DIST MACHINE and let them curve it for you. They will ask how the engine is built, any special cam and rear, etc. The machine will also verify correct movement in regards to the breaker plate and shaft bushing (spark scatter).

The springs (12192) and weights (12128) are under the breaker plate (12151).


The VACUUM ADVANCE canister is also adjustable w/ shims and spring pressure -.


If you had a 57 WSM, all of the different OEM curves will be shown. The MPC will give you the differing PN's.

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