Flywheel question

[jeffbcn]

Been a while since I posted here and know of the wealth of knowledge with you guys. You have helped me put in the past and hope again.
I have a 47 thriftmaster with a 235 truck motor built in 1962. I am going thru a major rebuild and came across another problem. My flywheel is worn out, cannot use it anymore. The casting number is GM1. My builder a says it's 10 inch with three pilot holes.
What I don't know is what it's compatible with. I do know that 6 and 12volt flywheels are different. This one is 12volt.
My local napa lists one as 10.4 inch from a 62 chevy car. Since it's aftermarket I can't match casting numbers. Is that the one I need?
Any comments would be appreciated.
Thank you.