I've overhauled a half dozen OS and Saito twins. Good info from Bert.
I use bearings from Boca Bearings, all standard clearance and hard chromed. Clean the rod bolts and threading with brake cleaner and air. I use 100% castor for torque lube and torque the bolts to spec for steel socket head cap screws. IIRC, something around 0.45-0.5 n/m in two stages.
Getting ready to do that very thing this morning.