[racer]

Well...

Its not a real turbo (and original '79 US spec turbos are $22-35K depending upon condition and origonality.

It's not a "correct" '79 SC which can run from $8k-$18K

So. now the pricing is all up in the air.

There is no such thing as an '89SC as you mention that is what the tail is from. I assume a type happened here.

As an SC, you don't mention mileage or accurate condition of the motor (compression or leakdown numbers would help here)

Is the Guards red paint orginal? Can you spot the original cover in places like door jams, engine compartment etc?

I assume the car has "SC" brakes, despite the flares and larger rims?

I would price it no more than 10K. I just don't see much "value" to the car given so many unknowns as well as its non-original like condition/appearance.