318 Dis-assemble & Assembled 1st time
The top two rings are compression rings and control just that. If you are getting oil past the pistons it is from the oil (bottom) ring.
I had one of my first motors I rebuilt use oil in one cylinder upon removing that piston I found that when I installed the oil rings on that piston I did not notice that the seperator had overlapped and wasn't "butted" causing the oil rings not to have enough tension. This lead to the oil consumption.
Chuck