Re: Make sure my thinking is not flawed
I know it has been a while since you posted this, but keep in mind that a reduction in RPM is not ALWAYS paired with increased MPG.
The gas V8, if it turns the same as a basic 454, should handle prolonged 3500 rpm quite easily.
(Usually, this sounds like the engine is screaming.)
In the old Ford 300/6 cylinders, you could drop the RPM's down to 1200 at 60 and it would get better and better MPG.
However, when we tried the same thing with the 4.3 Chevy V6's, much below 1700 and you started to go the other way.
The ford 300 had a 3600 redline, while the 4.3 was rated for 4500...but would take 5000 without trouble (as long as it was loaded at that RPM.)
The key is to find a chart of your engine and find where your optimum torque and HP crossover. In that few hundred RPM range, will be your best MPG.
If you already know this, sorry.
Just trying to help out.