The TB spacer helped out alot in tp end. I can feel the truck pull harder, and climp MPH faster. The Flowmaster muffler helped out even more with low end power. Before without either I would dog out in first with the AC on. Not it doesnt. My K&N intake is on backorder right now, but will be here pretty soon. I'm running the truck wed at the track to see what she'll do. Hopefully it wont rain like it's supposed to. It was worth the money. Not hard to install the spacer, but its a ***** to get the factore intake box back on. I have to break off a couple of pieces, and make a exension for a vacuum hose out of a garden hose. I would reccomend getting a volant, or K&N Gen II before the TB spacer. You'll notice even more of a difference.