Hy Skybum, the only way one flywheel will fit both a 235 and a 283 is if it has two bolt patterns. There are two different tooth counts for the flywheels one for a six volt and one for twelve volt. As there were no V8s that used six volt electrics, you would have to switch to a twelve volt starter. Being that you have a 54, your engine rear crossmember should have the angle mounts, if it does then you can use a bellhousing from a 55B - 59 V8 truck, and all your linkage should work just fine, hope that helps.
