i think he's saying that the stock airbox is is very restrictive leading up to the maf sensor hence the y pipe upgrade and what not, at least i hope so, but i have to agree 3.5 would be nice but i dont think the 3 inch would hurt at all on the na motor, actually im sure it will improve flow. on the other hand, the srt6 esspecially with a pulley upgrade, might benifit alot from the 3.5.