They are different. Yours looks to be a hydramatic. I bet it has two dowels on the other side to engage the torus cover

David,

Thank you.

Yes, it has two dowels.

Rob

Rob, these pictures are from a 1952 308 with hydramatic. Appears the same as yours.

Rob,

A standard shift flywheel is completely flat, so this is for a hydramatic. The only possible difference could be between the larger Hudsons and the Jet. I don't know if they are the same.

Per

Per and Kerry,

Thank you!

The flywheel measures 14-5/8"

Rob

Hydra-matic flywheels were made as one unit (integral ring gear) and engaged from the front of car. Standard flywheels (as mentioned) were flat and had pressed on ring gears which were engaged from the rear of the car. You have the correct flywheel.

Thank you Russell,

I'll hang it up and have it ready for when the engine needs to come out.

Rob

A stick shift flywheel has only 16 bolt holes. A Hydramatic has about 30, both have dowels that are in place 180 degrees from each other. There are distinct differences in both flywheels for when applied to the '55-'56 engines. The auto flywheel for the '55-6 has 3/8-24 threads, '51-'54 is 5/16-24. This also makes the torus bowl different and will not interchange. The torus bowl is deeper on '55-'56 transmission. I have found to use the '55-'56 flywheel and engine in your step-down, you need to have a spacer between the crankshaft,and drill all the torus bowl holes out to 3/8th's. I think this has all been talked about before?. The dowels for both flywheels are in the same place and same size.

Thank you Doug!

This board sure is a good place to learn 🙂

Rob