I should edit this, but I'll leave my incorrect statement as is. The stb does NOT fit over the plenum cover. Apologies to anyone that may have rushed out and bought both in the last hour and a half:
Not sure if this helps...
On an 05 thru 09 4.6 3v, the Boss 302 strut tower brace will fit over the Powered By Ford plenum cover...barely...but the stock hood insulation lays on the strut tower brace and when the stock hood is closed, the rear of the hood wants to lift up slightly.
Ideally, aftermarket hood or cut out insulation (maybe).
That Boss strut is a nice stout, heavy item. I just sold one of those and my old plenum cover a month or so ago. I did a test fit, that's how I know.