That is a substantial error, but it's only a difference of about.3 of a ratio, or the difference between a Gunson reading of 13.3 and the Sun reading of 13.6:1 in terms of the air/fuel ratio.

It is commonly accepted that most Mopar V-8 engines respond to an air/fuel ratio somewhere between 12.5 to 13.2 parts air to every one part of fuel, or a ratio of 12.5:1 to 13.2:1, and being able ...