Here is how you do this correctly:
Take the block and head to a machine shop. Have it tanked, bored, and new aux shaft bearings installed. You will pay less for this than you will for the equipment to do it yourself, and they will tell you what size rings and pistons you will need. Then you have them install the new pistons onto the rods.
If you are interested in the process, after honing the cylinders out you would need a set of telescoping gauges, which you use to measure the inside of the cylinder, then you have to use a micrometer to measure your gauge, and compare to the stock size of the cylinder bore to determine how far over-bore it is.
There is a special tool to do the aux shaft bearings. It is expensive, but not really hard to use. I just take the block to the shop because I would have to do over 100 sets of cam bearings for the tool to pay for itself. I'm not building that many engines.
If you really want to clean those pistons up there is a special solution, pretty easily available. IIRC it is called "gasoline". Use some fresh gas and a tooth brush. But in all reality, if you are doing the rebuild correctly and having it honed you will probably end up needing new pistons. The only reason to not hone a cylinder is if it is still at stock measurements with no taper. Taper happens because on most engines the piston doesn't sweep the full length of the cylinder, the notable exception being the early 302s, before they made the sleeve longer.