Looking for a new flywheel for my 460 project, and I am finding that I know nothing about what I am looking for.

Original engine was a 460 from a '79 3/4 ton. I have a new engine that I am using, but I have absolutely no idea what year it is. Block casting is the same, but I cannot find the head casting number. So I don't know what type of flywheel I need (ex. Internal vs. external balance, tooth count, clutch disk diameter)

Any help is appreciated.

 

Is it going to be auto or manual? Also is there a weight behind the harmonic balancer? That would mean its externally balanced. If the engine is a 79 I am pretty sure it will be external. Hope that helps.