AFR question

[dipso]

I have an internally stock 2.7. 1975 if that matters.
PMO 40's, MSD 6AL, JB racing distributor and all the other goodies to make everything work. Proper wires and everything is perfectly balanced at idle and 3000.
Do you think my AFR is so low because my rings are so old? I seem to run best in the 10's. I have tried 12.9, no way.
I am about at 11.4 right now it runs good, just get a few small pops out the exhaust.
If I put it it down to 10.1 or even 10 .5 it runs the best.

Could I be getting such a low reading because of the poor condition of the rings. I have about 140,000 miles on them and it blows a lot of smoke.
Will the LM2 pick up oil blow by or smoke and count it as AFR?

I'm thinking that might be my problem. I keep shooting for the ideal AFR reading but considering the LM2 is picking up exhaust smoke as well as fuel it is showing a lower number and I shouldn't be concerned about it until I get around to getting the lower end done.
My Air/ Fuel ratio might be good it is just the numbers seem low due to the bad rings.

I'm trying to stay away from #s in the 10's because that much fuel will wash the oil away from the cylinders and cause pre mature wear, I heard.
I don't really have a choice, it is what it is.
Just wondering what you guys think.

[Steve@Rennsport]

JMHO,.......

Its almost impossible to tune a tired engine with a lot of blowby and rich AFR's add to your troubles by diluting the oil and washing the cylinder walls. Sooner or later, a rod bearing will fail and that reduces the engine to junk, in some cases.

I would recommend doing a leakdown test, but you really need to rebuild the engine properly
if big numbers show its going by the rings.