who is running MRL (BAM) Lifters without lifter bore sleeves

Are you sure you did not miss a oil galley plug. I missed the one below the distributor on the drivers side once.
You know you can drive anything on the street these days and call it a street car, but that is almost the same build I have for a strip only bracket car, same heads,same rockers(they are beauties),eagle "H"
Rods. Pretty serious motor. I have not seen a set of the lifters that you have, but my guess is the cutaway(oil band) in the lifter body combined with the lift of the cam is partially uncovering the huge oil supply hole that small blocks have.
The comp cam lifter should fix it,because it does not have an oil band. That is assuming your lifter bores are in good shape.
Just make sure you inspect the lifters routinely for wear.
If there is such a thing as a drop in roller for a small Mopar the 828 is it.
I am going to check the plug also. When I take the distributor out.