Im probably just going to run it 50:1 ...
That is a dangerous assumption.
Making the Oil/Fuel Mixture "Richer," inversely brings the Air/Fuel Mixture "Leaner."
Lean Air/Fuel mixture is the dangerous one.
I would run 56:1 if that's what the previous owner has been running. Take a look at the next top end to see how it looks.
You need to adjust jetting to change Oil/Fuel mixture.
This will require tuning, multiple plug chops, and being certain you have maintained a stoichometric Air/Fuel mixture after changing the oil/fuel mixture. -BIG DAN