This is very old data, and when I say old, it was 20-something Ross doing the swap and I just turned 49 LOL. However, I am with Jay, the Performer falls off too quick for anything more than a stock 352/360. I really consider it a weight savings only
I ran my 270H 396 w/ stock D2 heads and headers in my truck with a T intake, then swapped a 428PI (very nice change from the C5), then bought a Performer FE when they were new, swapped it on a Saturday, then swapped it back the next day, because iit lost power on the whole curve. Between those two events was trying to tune it to get some power back because this was the "newest FE intake on the streets" and I couldn't believe how much power it lost.
Later, when the base of the PI rotted, I swapped a Street Dominator and couldn't tell the difference from the PI. That intake stayed on there until I built the 445 a few years back and I sold it on the forum. In fact, I wish I would have kept it.
D2s and C8AE-Hs flow about 210-230 cfm depending on valve job, Joe would know more on the intake numbers, but my experience is that they really like the SD and SM.