unfortunately the '89 is unique on alot of things electronic. If you have another year and need the plug at the dizzy, one off a caravan would work(I'm fairly sure).
I think stating 92 3.0 , there wasn't a plug for the injectors either at the firewall, and if you needed injector harness you have to buy the entire wiring harness.

dave h.
'89 Raider V6 5spd;Aisin Hubs;; Gen2 LS: frt. brakes, rear coils;U.C.arms;R.trailing arms;idler arm; rear LSD axle w.disc brakes ;2 battery system for Dog's fan; relocated ECU; custom bumpers;J.Baker receiver;Conferr roofrack; t-bar crank.