The owner's manual in my '05 Silverado (5.3 liter) states that the engine can run on ethanol. What parts are different from a normal 5.3 liter? How does the computer know to adjust for ethanol?

 

The fuel system is larger, and has larger injectors. There is a sensor then can tell how much ethanol there is in the fuel and adjust the injectors accordingly. You will get less MPG with ethanol, cuz it has a lower stoich rate, but it is usually cheaper, so you have to do the math and see if its worth running. You may also get a little more performance out of it since it is a higher octane fuel.

 

What he said.
P.S. Be sure to tell Magnacharger that when you order your Radix.