Ok, first off if you have the K&N intake, you install that 1 inch throttle body spacer it is going to raise your throttle body up 1 inch and guess what.... youll be cutting the crap out of the heat shield on the intake to adjust for the height.
Now for the bad part..... The Airaid throttle body spacer states: Dodge Throttle Bodies The PowerAid spacer incorporates a helix bore that spins the incoming air charge. The increased combustion efficiency provides torque and mileage increases. Installs easily in under 30 minutes. Detailed instructions are included.
They claim that the air "spins" and mixes with the fuel to cause a better burn..... Great idea for a CARBURATED engine but ours are fuel injected! Where does the fuel get injected? Right into the cylinder.... following me here?
Dont waste your money on one.... I bought one for my 4.7 and yeah it had a cool "whistle" when you stepped on the gas, but that was it. Actually some people thought I had a vaccume leak... When my 01 with the 4.7 got totaled I didnt even bother taking it off the engine. Take your $100.00 and buy yourself a nice aftermarket ACCELL or MOROSO coil and upgrade your plugs and plug wires. -Or- Save up a few more dollars and buy one of the Fastman throttle bodies. He is the GOD here when it comes to doing the throttle bodies and doing them right! Great guy to work with and will NOT BS you.
You dont have to take my word for these spacers not working Read this and judge for yourself:
http://www.truckblog.com/story-444-fuel_economy_myths_throttle_body_spacers