Thanks Gadge, in those days at least, Briggs' engineers knew what they were doing, so it appears that the chrome plated rings can be used in aluminium bores. Did the chrome plated ring sets come with chrome plated steel rail oil rings? I don't know how the ring pressure from those steel rail rings with expander, compares with the pressure from cast iron one piece oil rings. If the pressure is the same, it should work.
