Ok guys I picked up a a6 block at the junkyard. The cylinder walls had some surface rust on them that came off with some wd-40 and a rag. Do you think I need to hone out the cylinder and do I have to put new rings in if I do? Im not going for boost or anything just a dd

 

Depends on how smooth the surface is. I would spend the few bucks to get it done regardless though.

 

The walls are pretty smooth. Could i get away with honing and reusing the old rings or should i get new ones? And will standard size be good? Also are the d16 and d15 pistons and rings the same?

 

you should have the block measured and decide.

Get the deck checked to see if it's flat and check the cylinders to see if you can get away with a hone without a bore.
And if you do hone, get new rings.

 

Ok I will post back with results