Well, before shelling out $200-300 for an aftermarket intake system (and not being able to make up my mind which one to get) I decided to try an idea picked up on this site. Cut three 3" holes in bottom of box, cut mounting plate to match holes in box.

A friend bought a VHO identical to mine except color, and had dual in/dual out Xcelerator muffler installed and K&N filter in stock airbox. My exhaust is stock, have K&N filter and airbox mod above. We made 3 runs (2 from stop, 1 30mph roll) I won 2 of 3. The one loss was from stop, we ran from 0-shutoff with my bumper at his front door the whole way. So the airbox mod (free) made roughly the same difference in power as the aftermarket exhaust (not free) all other things being equal. This is the first time we ran the trucks against each other, really wish we had made a baseline run. We did this a week ago and I just realized that I could swap in another stock airbox and run again, but as of yesterday my truck now has the same exhaust he has so that won't work.

Sorry for the long story, just wanted to include as much info as possible without writing a dissertation. What do you think? Could cutting three holes in the stock box (about 20 min. total) with stock inlet tube displace the gains made by a freer flowing exhaust system? This little "real world" comparison seems to say so, but what have you guys experienced?

 

Mine feel and sounds louder. I'm also getting a MIT tube.

 

now if i make a custom intake... would i be wise to leave the stock airbox and do the airbox mod or run it all the way to the bumper with a cone filter?

 

i think either way would work. do whatever you think is cheaper and spend money on other mods, like e-fans (LS1 or LT1) which are cheap

 

Speaking of e-fans, does anyone know why Chevy did not change the intake tube one the '05 trucks? I checked one out and with the e-fans there is MUCH more room between the TB and fan shroud. The intake tube on the '04 is obviously designed around fan shroud fitment. Looks like the options would be wide open (literally) for a less restrictive intake tube, but they used the same one as the '04s.