I've searched but found nothing while reading on N/A build thread! What is SCV? Please don't shoot me!

 

Secondary butterflies valves that run through the intake manifold. Used for cold start ups or something. Only 91-93 have them.

 

close but not entirely true, iirc the 89s to early 93s have them and reduce vacuum to your pistons when decelerating along with restricting the air flow. if it's not a full race engine you're building i suggest you leave them in.