I have the same gun. My father bought it in '58. His/my pet load for is is 66 gr imr 4350 behind a 180 gr Nosler partition. Without any pressure issues this comes out of the tube at ~3130fps.
It's a very good shooting old beast that I have largely retired.
I have taken 30 + youth hunters on their first or second turkey hunts.........I'd recommend against a tight aftermarket turkey choke, it's the real reason for many misses. Any better 3" cartridges with 5's or 6's will work. By all means put some after market fiber optic sights on the gun. And...
I've been doing some predator control on a private ranch for the last several years.
They have been de-nuding the creek corridor and that takes years to grow in that desert enviorn.
My grandson said a week ago when we pulled traps and caught 2 "Opa this is the coolest thing ever!"
And by the way...
My Ruger American Predator prefers 142 gr Accubond LR. I say don't get too married to one brand O bullet. I built loads with Bergers, Hornady and Noslers to discover which my gun likes best.