I had modified my stock box with 2ea 2" dia holes cut in the front of it for ram air and a 5-ply AFE filter.
Ran this for approx 2000 miles, but replaced with it the AFE Stage 2Si (closed box) with the 7-ply filter for fear of rain getting into the previous setup.
I've ran the AFE 2Si for some time, its a good idea with some rough edges. (not thought out completely) ... To inspect or change the filter, I have to take the whole thing apart and the horn that attaches to the filter box doesn't line up very well, so its under some extreme tension. Plus, I have to disconnect the rad overflow hose to check the filter. The box doesn't fit up exactly with the foam seal on the fender. It has 4 clamps for the intake horn. If you are not extremely careful when you inspect or remove the filter, it can get damaged rubbing against the sharp edges of the box because the filter just barely fits in the box. Details, details...
Now, I have the PSM system with a cool hose from DPP with only two clamps. This retains the stock intake box for best fit and service. I'm running a Amsoil Eaa stock filter and have the stock AFE 7-ply to try later.
Go to
Performance Systems Manufacturing, LLC and check out their new system for the pre-03 trucks and also check out their dyno and road test data.
You want to keep hot engine compartment air out of the intake system. Especially if you are towing.
Hope this helps,
Louis