Different engine installed so VIN doesn't match engine. Engine didn't come with computer (ECU/ECM?) Need to find the correct computer. Gave VIN from the truck to Ford dealer but couldn't narrow down which unit would match & work. HELP ASAP to get my son OUTTA HERE!!

89-92 if no EGR, only thing you care about is if it's auto or manual, and if it's federal or California emissions. it's cali emissions if it has a mass air sensor, federal (most common) if not. just get one from a scrap yard.