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I find I am in need of a new flexplate for the marine V8 (missing ring gear tooth and attendant damage). Are all of the Ultramatic flexplates interchangeable from 1950-1956?

Thanks

Guess I'm a little surprised to hear that the marine conversion uses a flexplate and not a conventional flywheel. You'd think without the weight of the torque converter, a flywheel's weight would be needed to obtain decent idle and low-speed operation. Are you sure you mean a flexplate?

3 part numbers listed--23rd to 54 reg Ultra, 54 GS, and 55-6. Not the greatest pictures in manuals but it appears the circumference for torque converter attachment bolts may be one of the the differences. Can't tell if any different on overall size anywhere else or in crank bolts.

The 55-6 also have a sort of pad arrangement for locating the converter bolts the earlier ones do not have. Since those later converters have basically the same exterior, may be part of why there is a separate one for the 54 GS. If that were the only difference though, would have thought the 54GS and 55-6 would be the same.

Quote:

Thanks HH & O_D

It is indeed a flexplate, I assume that the mass of the large drum & planetary set in the reverse gear may provide enough mass in lieu of a flywheel. The only function seems to be to provide starter engagement, so any of those that HH mentioned should work as long as the crankshaft bolt pattern and the diameter and number of teeth on the ring gear are the same.

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