They can take a few degrees advance in stock form, like 5-8. But 12 is probably too much. If you need 12 on a stock motor, there may be something else going on. The one issue is the mechanical advance. When I am rebuilding a distributor (a 2403 in the case of a 57), it is not at all unusual for me to find a missing spring, broken pivot or frozen weights. Sometimes, there is just so much gunk and dirt and grease that the weights just cant move like they should or sometimes at all. Also, if the end play between the housing and gear is excessive, and depending on how the distributor has been set in the motor, you end up with somewhat erratic timing settings or an unstable timing curve.

But there are a couple of issues to add to the problem. If the flywheel is not original to the motor. Different years have different timing requirements, and/or different flywheel's may have slightly different marks as to tdc engine to engine. One of the issues for us is there is no real easy way to determine tdc with the motor together.

So you are stuck with what you are stuck with. What I might do is first, set the timing at tdc at the flywheel bb. See how it runs. From there, see if you can get your hands on a dial back timing light. Advance it to 5 degree btdc and see how that runs. Then advance it 2 degrees at a time and see what it feels like.

Also, and I am sure you know this but to be complete, make sure the octane selector is centered on the hash mark on the distributor pad. One way to do this is to put the motor on tdc at the bb, trace the no. 1 wire to the body of the distributor and put a mark on the body of the distributor directly under the center of the no. 1 cap tower. Remove the cap, loosen the bolt on the octane selector hold down, center the hash mark, tighten the bolt, loosen the screw on the clamp and move the distributor until the rotor is at the mark you made on the body. Tighten the screw. Now you have your base line set.

Start the motor and use a timing light. Readjust the distributor to tdc if necessary, using the screw to loosen the clamp, not the bolt on the selector plate.

Now you can start advancing a few degrees at a time and see what the motor likes.

Last edited by Dragsix; 05/19/2025 3:55 PM.
Mike