The round ring gets pressed into the front upper balance shaft hole. it blocks off the oil passage down to the main bearing, you can use a bushing installer or flat plate just slam it in there flush, I always added some retaining compound because we had it there Just be sure it goes in straight and tight, You are now done with the upper shaft area,
Take the stub shaft and slide it into the oil pump in place of the lower shaft, where the flats are clamp it into a vice ( be sure to leave clearance between back of oil pump and top of vice so the gasket surface doesn't get scratched, clean oil from threads and install the one bolt with some blue thread locker and torque it ( I think 45 lbs, whatever factory is for the bolt to balance shaft)
Install your oil pump to block, take chain and both gears together and slide them into place, If I recall teeth on the small gear are to be closer to oil pump- don't pay attention to timing marks sonce there are no balance shafts, you can dummy them up to check alignment of the big and small gear, that's important. Once you figure direction install the woodruff key in oil pump, slide gears and chain together on crank and oil pump- BE SURE KEY DOES NOT FALL OUT!
Next put a box end wrench on the other bolt, be sure no oil in oil pump threads, again blue threadlock on threads, deep well 6 point socket and tourque the bolt
( The box end wrench will spin up against your socket so you can torque it - I think a picture of that is on my facebook page.
Hope this helps,
Dad