It is obviously not true that the pre-88 and 88 fiero's are totally different cars. They share alot of parts: engine (including intake, sensors, ecm, ...) , transaxle, central chassis, ...

It is true that they changed the suspension for the 88 fiero. The rear was completely redesigned and the front was partially redesigned (spindles, front shocks are interchangeable). That said, i think that Knestis hit the nail on the head. If you take all the best parts off each of the two cars, in order to create one "best" of all years car, that car still is well w/in the class performance, for *both* the ITA (v6) and the ITB (i4) fieros.

Also note, whereas the 88 suspension is considered better by most, it is not obviously so, and has been the subject of much debate over the years. Especially so for the front suspension, where the unsprung weight is lower for the pre-88 cars.

And, there is no "weight break" for the 84-87 fieros in ITB. [/b]
Last comment first - I have no idea why there is no weight difference in ITB, but IMO there definitely should be.

Now... if it were a simple matter of sharing some key parts, we could also put the Chevy Citation on the same spec line with the Fiero. The X11 had the same basic 2.8l engine, transaxle, and suspension as the early Fieros. Okay, so the front drive engine and suspension on the Citation ended up at the rear of the Fiero, but what possible difference could that make?

Seriously, my point being this is not about a few shared parts. It's about the front suspension of the '88 having a far better camber curve than the off-the-shelf Chevette (yes... CHEVETTE!) pieces on the early cars. (I'll gladly trade away the insignificantly lower unsprung weight for a camber curve that works, thank you very much.) And these pieces are all attached to subframes that are NOT interchangeable between the older and newer models. That makes the important parts (the a-arms and subsequent geometry) non-interchangeable as well.

At the rear, the early cars have a nasty bump steer problem that was fixed with the '88 redesign. But you cannot simply bolt an '88 rear cradle/suspension to the early chassis... in order for it to fit, you have to make modifications that are against the IT ruleset - i.e. you have to move the upper suspension attachment points.

Given the limitations of the IT ruleset, these are in fact, different cars. I repeat... combining them would be a bad precedent.