First off, credit where it is due. A bud sent me this link- http://brazeauracing.com/mustang/airdam.htm
It details a front air dam as used by himself and Bondurant Mustangs. The only reason I added anything is I found some info/tools that worked well for this mod.
It is a front air dam from a Bronco II or Ford Ranger of the same vintage as all of the Bronco II's. He lists it as Ranger only, but I found that the Bronco II is exactly the same. He ordered a brand new one, and I found that my local bone yards want $10-15 for a used one.
This is the best dollar for return of any mod I've done to my car. I love the look, it fits exactly where stock air dam goes and it doesn't get much cheaper. It also looks OEM in my opinion. Sorry, no tech on added air to radiator, or better aero. Draw your own conclusions, but please post any reduced temps under controlled test conditions.
I am counting on the fact that you saw and read the brazeau link above, for the following to make the most sense.
The ribs shown here came off very easily with a 2" cut-off wheel. The original link mentions a belt sander, which I dont have. I think a jig saw with a coarse blade would also work well.
If buying used, the air dam may be less than straight. I used a heat gun, and reformed it, which worked very well.
If you mark the center of the lower radiator support and the center of the air dam it makes it a bit easier to fit. I also slotted the holes for adjustment with a dremel tool.
The finished height of the air dam is Approx 4" vs. about 5.5" of the stock air dam. This is with Steeda sport springs on a 92 fox.
As the original link states, this air dam is substantially lower, which is one reason I went used vs. new. I also picked up two, just in case I ate a cone or curb. I have had the air dam on for about 2 months now, and no substantial whacks so far. I hope ya like it.
For additional info see this thread in RR/AX forum: