I have contacted aFe about using the tube with the stock air filter chamber & their performance filter. I see very little increase in IMAP at high (6300) rpm with the stock air cleaner which is the same as used for the Hemi. My concern is strictly reduction of IAT.
I suspect the "air chamber" is the box in front of the water neck but think any effect on low end torque is minimal because:
1) a six with a single intake has very even flow to begin with.
2) 38" of 3" tubing (about 260 in3) in front of a 222 cid 6 makes a very good plenium already particularly at the low end.
3) any reduction of surface area exposed to the 200F air coming off the a/c and radiator is a Good Thing IMNSHO.
Of course only with proper instrumentation (a dyno) can you be certain but can tell a lot just with OBD-II (see here
for my personal experiences with low cost scanners but if you have a laptop, netbook, or Android tablet/smart phone the investment is less than $50) - IAT and IMAP are just two of the displays available.