Its only like 20 bucks more than the 88 damper, and I heard it fits right in, but I was wondering if there is anything i need to know. Because I thought I read some holes needed to be filled, and I think I heard it had to go in backwards.

 

I'll have one in a week or so.. I'll take pics and post a writeup about it.

-Tesla

 

When I installed mine in my 88, I asked whether it had to face backward or forward as the pictures of the 89-91 showed it "backward", with the PD facing the firewall. I was told it doesn't matter, so I installed it with the orientation the way it came off strangely enough from the parts car and the way the 88 sits, with the PD forward.
The only thing is that the 86-88 has a raised area on the pedestal of the rail which requires a longer bolt that you will pull out when you pull it out.
The 89-91 has the same size bolts and no raised area on the pedestal. The bolts are therefore the same size that mount it to the block on the 89-91.
Also, be careful of the oil injection lines as they are in that area when undoing the PD and the fuel line. They are brittle and break easily. Install all new Fuel INJECTOR hose. Not the regular kind of fuel hose. Its specific to injection systems and costs more but will take the added pressure. You have to specify this to the parts guy and then make sure he hands you what you asked for .
Ralf