I know this must have been asked before but I could not find it in any discussions. Need a little help. Is the 1953 10w oil for the transmission for a 53 New Yorker equivalent to a 10w-30 oil of today? The old oil did not seem to have the same viscosity when I compared the two ( Assuming the previous owner put the correct oil in ). Also, consider that the old oil was sitting in the transmission at least 15 years. Can I use the 10w-30? Rookie