I am copying this from a similar thread about a DIY 4.7 intake. First to answer your questions.
I'm look for instructions on what specs others had to take. Specifically, what do you do with the AIT. Is it easy to relocate into the new CAI. I was thinking of drilling a hole in one of the tube with a spade tip drill bit and then putting in a rubber grommet if I can find (anyone know where I can find an appropriate size grommet). You can do that. Relocate the IAT near the filter, or in effect, away from the engine so the temperature readings are closer to the actual air temperature versus being affected by the radiant engine heat. Grommets are a few cents at local hardware stores. I am unsure of the actual size, but there are diagrams on other forums that could help, or have someone help you at the store. You may be limited by the length of your IAT, but you can splice in wire to extend it, or buy an extension.
Also what do you do with the vacum tube/breather hose attached to the stock intake? I thought I might use a pvc tube with a screw in clean out port and install a hose adapter I can clamp too in the port cover? Any other ideas?
You can reattach the PCV into intake, or add a small breather filter ($5-10 at an autozone/napa/etc). The breather filter is the cleanest approach unless you have Emissions checks, then you will need to recirculate the gases.
Also anyone know the warrenty status doing such a mod? I've also been debating a K/N cone filter or if I should use a high flow dry filter because of the theoretical warrenty issue there (although it may be moot if I would void the warrenty anyway). Incidentally has anyone actually had a problem at a dealer with having a oiled drop in filter or is that issue not really inforced. It seem pretty absurd to say a high quality filter such as a K/N would void your warrenty.
I have no personal stories, but we have no MAF sensor the oil to Fubar. There is a clause on aftermarket products that claim they cannot void your warrenty. On homemade applications it may be different.
This following information is basically outlining why the BFI from AirFlowInnovations is the best choice, and if that is completely out of your budget, I hope you can take information from this post and apply it to your build.
Bernoulli's principle is used to explain fluid dynamics and how fluid can be accelerated by the change in pressure. It applies to gases that are unchanged as well. Air entering the BFI at the Large 6" opening on the high-flow filter will flow into the TB and move from that 6" opening to a 3.5" elbow that mates up with the Throttle body. A property that effects Bernoulli's principle is that of friction and resistance. The air entering the intake is moving so fast it is unable to change in temperatures enough to affect the principle itself. The design of the BFI allows it to reach air from a pocket away from the engine heat and in route to the Throttle body, the flow is extremely smooth without any friction or resistance
If you can make a HomeBrew intake taking the principle of (even if you arent able to utilize a gradually decreasing Diameter) smooth flow and velocity you will have a winner. Try to start large at the filter and allow it to smoothly flow from the filter to the Throttle body without any sharp decreases in tubing sizes that would cause turbulence (which negates the velocity principle and smooth flowing air). I think any intake with an open element filter will be louder and might enable a slightly better flow of air, but to increase performance and to add a killer sound, the large metal resonating smooth tube of the BFI is the best example.
I have no personal examples of a homemade intake on a 4.7 truck for you, other than what I have seen online.