915 R&P - What do these numbers mean?

[RarlyL8]

There is a set of numbers forged on the R&P unit for my 915. I presume they are part numbers. Do they have any significance?

915 318
345 0R

There are also two numbers hand scribed on the ring gear. Did the factory do this? What do they mean?

7180 0.15

[Geary]

7180 is the matching number also found on the pinion head. 0.15 is the backlash figure.

915 318 = 8:31 915 R&P

[RarlyL8]

Thanks!

[Henry Schmidt]

915 318
345 0R

That number located on the speedo magnet plate is just a casting number. It has nothing to do with the R&P ratio.

[RarlyL8]

I assume this is an 8:31 unit. How do I confirm it?

[Todd Simpson]

Count the pinion teeth.