Nope, it's the TPS sensor. Here's the deal. Professional Products sent me a Thunderbird TB but it has the Mustang linkage on it. So, I took the linkage out of my Edlebrock 70MM TB and switched it over to the 75MM one, unfortunately, the shaft is not as long because the 75MM has that adjustment spacer for the TPS sensor. I removed the TPS adjustment spacer and just bolted the TPS sensor to the 75MM TB but, that puts the TPS sensor vertical and not horizontal like on a Thunderbird TB. I'm just not sure if that matters or not. The TPS sensor is now rotated vertical instead of being horizontal. Follow me?
Also, Ed, do you know what size nut goes on the brace that your air dam cover bolts too? The air dam cover is right underneath the radiator and is a black material.