Being as Dave brought this back I figured I’d update it a bit.

This is the second 4 speed adapter I built. It’s pretty basic, just the modified factory spacer plate and a Poly flywheel cut down to work with a 340 ring gear (69bee did the flywheel work for me about 25 years ago).



As noted above the Polys only used 6 7/16” studs instead of 8 so you have 2 empty holes in the crank flange. Six is really sufficient until you start getting into engines making a lot of HP or getting a lot of abuse. If a person really wanted to, the flywheel is capable of being drilled for the additional 2 studs if you really feel you need them.

If you’re into doing extra work the flywheel flange on the crankshaft can even be drilled and tapped for ½” flywheel bolts instead of the 7/16” studs and nuts. Wildcap even used to sell a fixture (drill and tap guide) that might still be available to make sure the holes and threads are straight.

I did find with this setup that a fairly thick spacer was required to space the starter correctly.





I used this particular setup for test starts while the Hemi that is going in the 37 Dodge was on the test stand for the last several years. This is also the same basic setup I’ve been using on my 57 Plymouth for the last 10 years with no problems.


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