This was on Autotrader a few years back. A little more in depth than just removing the doors though.
Here is a link, Autotrader - page unavailable
(Link works for me, not sure why it says unavailable)
Just suggesting that San Diego and Yellowstone are vastly different elevations and that will have an effect on engine performance, depending where you were and what elevation you were at.
Why Horsepower is Calculated At Sea Level:
An important factor in figuring volumetric efficiency is elevation relative to sea level, at which the engine is operating. As elevation rises, oxygen levels are reduced, reducing an engine’s volumetric efficiency. The typical drop in horsepower at any...