I think I got mine from Jeremy at UPRHere's the stock style one.
https://www.americanmuscle.com/radiator-air-deflector-8793.html
Unsure who sells the aluminum one
Worked very well, it's a common mod for guys who race road-course/ auto-x...
Um as for a part# I would have to dive way way back in my thread to find it....
They are crazy cheap new, I think I paid $35 on ebay shipped...Im there!! I'll be looking to snag one from a ranger in the boneyard
http://brazeauracing.com/mustang/airdam.htm
They are crazy cheap new, I think I paid $35 on ebay shipped...
@wiseguyk just got one cheap on amazon