When you say "Trim Tag you mean the FISHER "body number plate"Yes?
A car could have been involved in a collision and the sub frame replaced with one from a wrecking yard donor car and those #'s might not match.
The rear axle housing ,if its the original, should also have the VIN stamped on the passenger side axle tube close to the center section.
1971 car it will be the 8.5" 10 bolt ring gear differential.
The front fenders should have the original VIN # stamped into them as well
Another source of authentication is the "IDENTOTAG" an early computer print out sheet on tractor paper that was stuffed into the car in several locations.
I found two for mine. One was stuffed into the springs of the passenger side bucket seat and the other was stuffed between the gas tank & trunk floor.
Sometimes they got stuffed up under the dash or under the back seat.
If the car is pretty much unmolested those print outs will still be there unless someone removed 'em.
Those printouts will have Every thing listed that the car came with,the assembly plant & will also have the VIN # in the box on the upper right hand of the sheet.
71 formula should have a VIN beginning with 22687 total production for 71 Formulas was 7,802.
Formula was available with 350 ,400 & 455 or 455HO
Base 6 cyl car (250 1v) would have a VIN# with 22387 - 2,975 total
Base V8 car (350 2v) would have a VIN# with 22387 20,047 total
Esprit (350 2v or 4002v ) would have a VIN# with 22487 20,185 total
Trans Am 455HO would have a VIN# with 22887 2,116 total
Sourcing a formula hood is not hard to do. They are available in reproduction or if you are lucky enough a wrecking yard (not so much anymore. The original Formula ram air air cleaner assembly is available in reproduction now too.
Step Away From The KOOL AID !
Last edited by sprint250 : 02-14-20 at 03:55AM.