I have a wrecked 1998 s10 with 4clylinder I am putting in a 1987 s10 pickup. They are both 2wd. I am wanting to know if someone could tell me or tell me where to go to find out the wiring info I will need to know.

 

Just take the old PCM out and follow all the leads from it. Those are all the wires you will need.

 

shnormo is right. But that is your engine wiring. I would swap the tranny too. All your interior lights should be on another harness. If you cut the old one out of the 87 just make sure you don't hit any of those wires. You may want to see if you can swap the gas tanks too. The 98 being fuel injected will most likely need more fuel pressure.