I know what you mean, I have looked at the specs for this motor and and seen where that pistons are numbered A,B,C, & D. and there was a gain of .0005 for each number, but never gave it much thought...
until now, as I have found out. it doesn't do a person much good, to put all the bells and whistles on, or mod mine like I have done if I don't take care of the basics.
as for matching the pistons to the same cylinder, that might be an impossible task. if they need replaced, we are kind of at the mercy of what is available.
the main thing is you don't want to put a "D" piston with a "A" cylinder, there is not enough clearance for the thermal expansion of the piston skirt. It will score the cylinder walls
looking at what I have on hand, all the pistons on the 084 and the 042 that I have in pieces, they all have chrome rings for both the top and middle slots.
I measured the 042 cylinders and there is no wear. I am thinking that perhaps my 084 was re-ringed at one time. I know I was not the first to open it up. but the damage to 3 of the walls was already done...
so I have 3 cylinders & pistons that are good to go. just a slight hone and new rings. I did come across a fellow that sends the piston and cylinder to a shop and has them fitted. specifically to each other.. I am thinking of going that route for my last one.
even though there was some wear on rod bearings. the journals all were between 1.4975 and 1.4978. but if needed the same person sells undersized rod bearings also.
so at the moment, I am in the waiting period for more freight to show up. so I can start putting this motor back together. and hopefully with the basics done and taken care of I might be able to see how this mod I am doing really works...