Check my thread in the FAQ section on putting the 89 steering wheel into an 86-88. It's not hard. If you don't want to wire everything up for the cruise relay, it's not hard to just put the 86-88 connector onto the 89 steering wheel, just splice the wires and leave the cruise main switch wire off. (It's a single wire).
There are 3 wires on the 86-88: Ground, Cruise Input, Horn
There are 4 wires on the 89: Ground, Cruise Input, Horn, Cruise Main
Don't have those pics for ya, but it's really not going to be hard at all to do that. It's a little bit more difficult to wire it up so everything works like it's factory, but that's what I did, and I have instructions in my FAQ.
From what I can remember, the wire colours in the steering wheel to the connector are the same between 86-88 and 89.
The absolute easiest way to possibly do this swap, is to get an 89 combination switch. (The entire thing with turn signal and wiper controls on it), and put it on the car. The car's connector will plug right into it, the 89 steering wheel will plug right in, and you'll get the nicer 89+ stalks. It requires no splicing or changing connector pins, it's bolt on and plug in. The cruise main switch on the steering wheel won't do anything though, unless you wire in the 89+ cruise main relay.
Good luck.
Link to my FAQ
(EDIT: Added more info)
