If you really want the best economy, go with a 2.88 rear end, put a shift kit into the tranny so it has a firm shift between shifts and run Biodiesel with a 3* degree timing advance.

Keep your tires properly inflated and the usual. Having to re-engineer the whole car for better fuel economy is too cost prohibitive and you will spend less on fuel than you will replacing motors and the like.

Also, you can use refrigerants like Envirosafe and get great cooling out of your AC and in most states it is legal. This move will save you about 3 MPG alone. It's made in Florida and for sale and use their as well.

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"Extremism in the defense of liberty is no vice and moderation in the pursuit of justice is no virtue!"

The Greatest Arizona Senator ever, Barry M Goldwater. I hope you can see from heaven how much you are missed.