I successfully did the '91 to '86 guage cluster change!
 

Yes I did. To start off with I followed a link here on the board to another site which had a pretty simple diagram of the two plugs on back of the cluster. To say the least (not to blast him or anything) it was wrong! I had my friend do the wiring while I repaired my oil line this weekend, when it was all done I connected the guages and to my suprise nothing worked but the speedometer. So I had to start my quest to figure out how to either wire my original cluster back in and waste $80 or figure out the new wiring. I went searching the wiring diagrams for both the '86 and the '91 in the Factory Manuals, and after a couple of hours I got it. I hooked it up and voila! It works, every guage works. Now my '86 thinks it redlines at 8k and registers 160mph! Woohoo. Now I need to get the info on how to actually (safely) let the motor redline at 8k. It is the original engine, and no fuel mods. Maybe a new computer, fuel pump and fuel injectors will do the trick. Any suggestions? Thanks

Whenever rebuild time comes around you could use the lighter '89 up rotors.You'll also have to use the 89 front counterweight and flywheel.They also have higher compression ratio that will give you alittle more power.

Care to show the real wiring diagram? Some of us would like to know! :D

yeah hehe post something usefull for the next guy who comes across your situation.

Fred

I wasn't sure anyone would be interested. Ok, I will do it. I'm at work right now, and I'm moving to a new house, but I'll post them as soon as possible! Like a dummy I didn't write down where the wires went so I'll have to pull the guage, but that isn't too hard. :)

I think that are several of us that would love to get that post.