Hey Dave,
Do you know if the shimmed engines were align bored when built at the factory? I thought they had different diameter main bearings making it difficult if not impossible to align bore, thus requiring shims for final fit.
Carl
Starting in 1948 Chevrolet started precision aline boring the blocks and using precision inserts. Before 1948 the aline boring was done to the bearings after pouring.
It is true that the main bearing sizes are stepped but that only means a special set-up is used for this job.
