The flywheel in my 55 has 168 teeth with a 10 1/2" clutch. However, the flywheel was bought new and installed by my older brother Bob, when he had the engine in his 57 Chevy. He bought the flywheel over the counter from the local Chevy dealer's parts dept. in about 1970. If I remember correctly, it only has one bolt pattern for the pressure plate. I have no idea what the original application of this flywheel was for. Chevelle??? Impala??? Camaro??? Perhaps it was for a pickup???
I have several parts books I could look at...but they don't list the clutch bolt pattern diameter, only the disc size. But I'm too lazy to do it right now...
The early bellhousing will accept Borg and beck style pressure plates A word of caution If you are building a high rpm motor don't run an early stock wheel they are pretty much the reason for ****ter shields.
I thought that the 'housing in my car was from a C30 truck. I have had it in 3 cars so far over the years. I decoded it in 2015 and it is a '55 Chevy piece. I also have a bunch of truck ones around, this was the cleanest one. I run an 11" Zoom clutch with it. I had to flip the starter ring around on this one. I run a truck bolt to the 'housing starter with it.