[69gmcc10]

Dont forget that the further you move things back the more effect it has due to leverage. Moving something 4 feet back from the center will be exponentially more effective than 2 feet. Also the fuel cell relocation and amount of fuel have an effect. Moving it from hi and behind the seat to lo and as far out back as possible with a full tank would be huge, and who is to say how much fuel is in thereat any given time effecting that ratio. There are also air tanks and compressors on the passenger side frame under the bed.