Besides just putting a piston stop in the #1 or #6 spark plug hole and rotating the engine both directions by hand (battery is disconnected at this point) and then marking the damper in between the two marks where the piston was stopped in each direction, you can do the following.

While not as exact as using a piston stop, you can take a 3-4” straight edge and lay across both the intake and exhaust valves on the #1 or #6 cylinders.  When the exhaust is coming up and the intake has just started down (overlap cycle), find that point where both valves are level with each other.  That will be TDC or so close it hurts.

Lorena, Texas (South of Waco)

Are both intake and exhaust valves of # 1  (front,. right side) closed   on the compression stroke ?  That would indicate top dead center.  If the crank does not indicate at top dead center then the ring is off (assuming the car is a sedan and not a Tbird).   I am assuming that the timing chain was installed correctly

If that agrees, then you have to move the rotor so it points to #1 on the cap while keeping the vacuum unit in the position where you want it .  It is  trial and error exercise to get everything in sync because of the way he distributor drops in..  You may have to make slight compromises on the position of the the vacuum unit



54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

This was my plan....

Prior to installing distributor, move crankshaft to TDC of #1 cylinder (front passenger side) as follows.  Turn crank CW while observing #1 intake pushrod (2nd valve back on passenger side), stop when it just fully closes down, continue power stroke until 0degTDC on damper scale.  Verify piston can be seen thru spark plug hole with minimal plug clearance.  Install distributor body into block with vacuum ballast aiming as desired for best maintainability, and even aim rotor to #1 direction if desired.  Personal preference was vacuum ballast aiming to driver side while rotor points forward.  Remember this is after distributor spins during drop-in.

....but it looks like my damper timing pointer says TDC when piston is nowhere near top of cylinder.

How would I go about marking damper for the real #1 TDC, or mounting new pointer to align with existing mark?