Add to the first post: "Spark Box"
Note that the 88-89 is considered the 'premium' set-up, and preferred donor car due to the most advanced the electronics were developed. 87 is second.
The turbo downpipe alternative is available aftermarket and is much less restrictive. The stock one uses, basically, a near-90-degree bend at the turbo outlet into the downpipe.
John B.