I agree with Rocky and have found improvement with the stock intake myself. The 400 in my 71 GTO with the Lunati BMII (.490 lift,292 adv.
[email protected], 110 lobe seperation, 104 IC) likes the stock better with my unmodified 670 heads than it did the Performer or my Torker, especially with a 4 speed. 60ft times dropped to the best the car ever did after going with a stocker, 1.80 compared to a best of 1.92 with the Torker and 1.95-2.01 with the Performer. Alot stronger in the midrange, up to my shift point of 5200. Go with the stock, better choice overall, especially on the street.