Suggestion?
Change oil to an inexpensive house brand.
Seafoam it.
Change again within 200 miles (and filter!)
Use a quality dino brand (Castrol, Pennzoil, whatever floats your boat.)
Run it 1000 miles.
Seafoam it, run 100 to 200 miles, change it again.
This time to a full synthetic, or at least a synth blend (again, a good quality one.)
Then start changing every 3000 miles for at least 15,000 miles, even if the oil and filter says it's good for 5K to 10K miles.
That ought to clean most of the crap out of the inside of the motor.
RwP