Bore the motor or the problem is going to continue due to out of round cylinder walls.

 

Bores were fine.

 

Brian, I know I mentioned this to you already, but I think a plate hone will help immensly. My theory is that this "newer" Gen5/6 blocks are light-weight casting and distort a bunch when the heads get bolted on. I'd hate to see you buy new pistons and you still burn oil.
I plate honed mine, and replaced with the same ring package (shallow oil ring). I went from a qt. per 100 miles to about a qt. to 1000 miles - good enough for me.
Look how distorted the bores are - the head bolts pulled the cylinder wall in, ring didnt even touch the cylinder wall by the bolts:

 

Vince,

I know we spoke of this but believe me, the bores had no noticeable distortion like yours. Besides, I have rebuilt many a motor with 100k mile with merely a ridge removal, re-hone and re-ring and no problem. Granted they were not high performance but mostly small block Chevys but never would I believe that could cause this thing to piss oil out the tailpipes and mess up my bumper.

If I find distortion when I pull it out, I will have it plate honed but as I said I didn't see it before and I may have put 1k miles on it since the rebuild. It has maybe 5-6k on it total.

I can't believe GM hasn't had a class action against them for this crap (like that would go far now).

Anyway, aside the bore issue, do you think I can fit those domes in there to get a little more compression?

Thanks for the help!

 

Vince,

I know we spoke of this but believe me, the bores had no noticeable distortion like yours. Besides, I have rebuilt many a motor with 100k mile with merely a ridge removal, re-hone and re-ring and no problem. Granted they were not high performance but mostly small block Chevys but never would I believe that could cause this thing to piss oil out the tailpipes and mess up my bumper.

If I find distortion when I pull it out, I will have it plate honed but as I said I didn't see it before and I may have put 1k miles on it since the rebuild. It has maybe 5-6k on it total.

I can't believe GM hasn't had a class action against them for this crap (like that would go far now).

Anyway, aside the bore issue, do you think I can fit those domes in there to get a little more compression?

Thanks for the help!

I think I read in the GM Performance catalog about the oil issues with the 502. I believe they list a part # for a different ring to cure the problem.