273 302 318 340 build

Swung by car store, they dont have the small plug. Dorman #555-008 crosses over to Papco #260-118 so thats ordered up.
Whats a good way to remove the plug? Im thinking center punch, then drill then thread a screw in?
Suggestions?
Main bearings are full groove, but rod bearings arent. Would grooved rods be a recommended upgrade?

Thanks
Steve