New rings or not...
 

I am in the middle of doing a valve grind to my 89 240sx (230,000kms), and i was thinking of replacing the piston rings while I was at it...

Does this sound reasonable? or should I leave well enough alone, and just put the head back on...

If I change the rings, should I change anything else, or can I get away with reassembling the connecting rods/etc with all the same bushings, etc...

if you change the rings change the crank bearings also.

I decided to leave well enough alone... compression was 140-150 before, and there is absolutly no wear on the cylinder walls. I'm scared if I screw with it, it may make things worse.

I did change the rear main seal and clutch when the engine was out anyhow.