FYI - I had a brassy sound and or knocking a bit, nothing like a bad rod , while under load or crusing around 50. I redid the timing, adjusted the valves about 4 times to be certain( in case slop in rockers as ealier comment and added Lucus oil addative , heavy oil 50% and the noise is gone. I don't know!! Just my 2 cents.

'57 3200