It will work. I have the same one in my tractor. The bolt pattern on the round top plate was the same as the original on the 60 year old beast.
You'll have to modify it to work in the Fiero, but it will work fine as long as it's 0-90 ohms. I got mine from egauges.com (I got all of the gauges from there, too). I used the Summit sender on the Fiero because I was ordering other stuff from them at the time.
1986 SE Aero coupe.
3.4 DOHC swap is complete and running, now just have to finish the rest of the car...