I can't speak for the 4.6 2v.
But way back I used them for my 09 4.0, 15RWHP, 2RWHP with the blower.
On my 3v 4.6 that with the o/r h, netted me 20RWHP and 15 LBs after install. That was before I did cams.
Granted they are cheap, I've had no complaints.
Only pay the little extra and get them coated. I didn't my first time...yuck.
Been debating them or BBK, bbk seems to have some fitment issues.
But the two vehicles I used them on, they fit fine, and the 3v ARMOR coated, looked great and didn't rape the bank.
I had a friend in germany with an 01 with pacesetters, he was happy, got blasted for cheaping out, but claimed 18 or so was added to his uncammed build.