With a little time and effort, you can increase the performance of your engine by going from THIS.

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1 How-To Modify The V6 & V8 Throttle Body This modifying procedure is for the 5.2 and 5.9 V8 and the 3.9 V6 TB''s. With a little time and effort, you can increase the performance of your engine by going from THIS. TO THIS!

2 These are the tools I recommend you have on hand before starting this project. -Hand Drill -Bench Vise -Hack Saw -Ro-Lock 36 Grit Sanding Disc -Dremel Tool w/cutting Disc -Spray Lube -T20 Torx Bit -T25 Torx Bit -Cutter Tool (Northern Tool) -100 Grit Flap Wheel -150 Grit Flap Wheel -240 Grit Flap Wheel -13/64th Drill Bit -8" Flat File -Points File -4mm Tap -Four (4) 4mm x 6mm screws -1/4-20 Flat Bottom Tap

3 Clamp the TB in the vise as shown and using the hack saw, begin removing ONLY the airhorns as shown in the pic. Use caution when clamping the TB in the vise applying enough pressure to hold it but not enough to crack the side of the TB because it can happen. Using the 36 grit sanding disc, begin smoothing the remaining parts of the air horns and also smooth out any hack saw marks.

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5 Using the 13/64th drill bit, drill out the factory plug that covers the linkage adjusting screw.

6 Using the dremel tool with the flat cutting disc, grind down the threaded end of the screws holding the blades in the throttle shaft. DO NOT attempt to remove these screws without doing this because the threaded ends are braded and the WILL twist off inside the throttle shaft and then there will be no way to remove the blade. Remove the four 4mm screws using a T20 torx bit paying very close attention to exactly how the blades are inserted in the throttle shaft because they WILL have to go back in EXACTLY the same way.

7 Using the 8" flat file and rotating the throttle shaft, file down any burrs that may be on the throttle shaft. Otherwise, the shaft will become stuck in the throttle shaft bearing when removing it from the TB.

8 Clamp the TB back in the bench vise and begin removing and tapering the top of the bores back to the TB mounting holes. This will be a rough cut only and will be smoothed up latter on in the process.

9 Using the 4mm tap, chase the threads in the throttle shaft to remove any messed up threads caused by removing the screws and use the flat file to smooth the shaft.

10 After you have throughly cleaned the TB, especially the IAC port, you have the option to leave the TB casing unpainted...

11 ...or you can paint it using any color high heat rattle can paint you desire. If you do decide to paint it, be sure to stuff something inside the IAC port to keep out the paint. I use a twisted up piece of steel wool but any type of paper or rag will work. You don't have to be to worried about any over spray on the top and bottom of the TB casing because you'll sand all that off later. Using the 24 grit flap wheel, very lightly sand both sides of the throttle blades and throttle spring. This will come in handy later on in the process if you decide to mirror polish the blades.

12 Clamp the TB in the vise with the bottom side up and first using the 150 grit flap wheel, remove the paint over spray and then come back with the 240 grit flap wheel and polish the gasket surface. Light pressure is all that's need here or you will distort the gasket surface.

13 You are now about to begin the MOST CRITICAL part of the modification so TAKE YOU TIME AND DO NOT GET IN A HURRY!! Clamp the TB in the vise and using the cutter wheel, start removing the stepdowns inside the bores. SLOWLY start removing material until you can just barely feel a very small amount of the stepdown left. DO NOT use the cutter past the edge of the stepdown!! Rotate the TB in the vise to remove the stepdown all the way around the bores. Also use the cutter to complete the taper to the tops of the bores you created earlier.

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15 On the base of the TB, you'll see a small ridge that can be removed if you desire using the 100 grit flap wheel. It's not 100% necessary but will greatly help with the air flow. I'm very anal about square edges inside the bores, but this step is totally up to you.

16 Using the 100 grit flap wheel, start sanding down the cutter marks starting on the outside and working your way inside the bore. Light pressure is all that's needed here so TAKE YOU TIME. Working to the inside, once you get to the edge of the stepdown, slowly and carefully smooth the cutter marks until you see the line disappear at the edge of bottom edge of the stepdown and then STOP. If you go too far and remove too much material, all the work up to this point will be for nothing and the TB will be junk. Using the 150 grit flap wheel, begin smoothing and blending the surface starting at the back and working you way to the front. Only very light pressure is needed here as you are only

17 wanting to blend the bore and not remove any more material inside the bore. Using the 240 grit flap wheel, very lightly smooth and polish the inside of the bore and blend the taper to the top of the bores.

18 Using the 150 grit flap wheel, begin removing the cutter marks at the top of the bores and rolling the edge to remove the sharp corner. Depending on how deep the sanding marks are that were left after using the 36 grit sand disc on the top of the TB, you may need to start with the 100 grit flap wheel or you may be able to start with the 150 grit. If you start with the 100 grit, DO NOT go inside the bores or on the rolled tapered edge.

19 Finish off the top and the top edge of the bores with the 240 grit flap wheel. Using the 1/4-20 bottom tap, straighten the threads at the top and tap as deep as the hole will allow. The threads are tapered inside the threaded hole and will cause a very tight situation later on when you bolt on the stock air hat assembly or the S-bolt if you bypass this step. Now here's where the MAGIC begins if you want the mirror polished surface on the top of the TB, inside of the bores and the blades. If not, then move on to the re-assembly process. Using a 2 1/2" mushroom polishing pad in you hand drill, apply the aluminum polish to the pad. I use the Busch Aluminum Polish but you can any brand you wish. Using you hand, work the polish into the pad because if you don't, when you pull the trigger on the drill you'll get to wear some of the polish home.

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21 Apply just a couple drops of any type spray lube on the throttle shaft bearing and the center support between the bores. Begin reassembly by inserting the throttle shaft back into the TB and by inserting the blades into the shaft. The blades have to go back in the exact position as they came out or the holes will not line up for the screws. I highly recommend using 4 new 4mmx6mm screws for the blades and not reuse the old ones as the threads may be screwed up on the end. Start the screws in only a couple threads and the flip the TB over and apply a drop of blue locite into each threaded hole. The screw heads are facing down inside the TB and this step will insure they will not back out and cause you a big problem later on. Back the throttle linkage adjusting screw back until even with the TB case, snug the screws but do not tighten, then open the throttle blades and let them snap closed 3-4 time as this will center the blades inside the bores then tighten the 4 blades screws. Wipe off any access loctite on the throttl shaft. Slowly turn the adjusting screw out until you feel the blades working freely and then go an additional 1/4 turn. If the blades are working freely before turning the adjusting screw, then chances are you removed too much material and all you work has been wasted because the TB is now junk!

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23 Your modified TB should look like this after you're finished if you decided to mirror polish. Congratulations and ENJOY!! DISCLAIMER: USE THIS WRITE-UP AT YOUR OWN RISK! I CAN NOT BE RESPONSIBLE FOR YOUR INABILITY TO FOLLOW INSTRUCTIONS!!