ive been looking this up for a long time but not sure if it the actually stock one or really a performance one as stated
96-98 Mustang GT 4.6 4.6L Performance Intake Manifold - (eBay.ca item 220294738959 end time 12-Nov-08 16:59:14 EST)

if the link does not work for some people its a intake manifold saying its a new improved manifold that adds up to 15 to 20 horse power and ive read a bit off the customers replys in the feedback section and they say it worked for them as well

 

ask them who did the research and if they will provide proof of their claims.

 

Their claims seem a little suspect to me. Because if there were a plastic manifold that improved power (Other than upgrading to the PI intake, and heads), I believe there would be other places that sell it, and there just isn't. However I did find a performance manifold that will fit your car.... It's just insanely expensive.

Ford Racing intake

 

Steeda needs a better pic lol

 

Exactly.
A PI intake manifold that does not require PI heads and will give you 15-20 HP anyway?
Seems too good to be true to me.