The dampner wouldnt cause the timing to be out. Did you align the timing dots correctly? they should look like this. This is from when i installed my xp cam about a month ago.
Did you put the cam thrust pate back on correctly? or back on at all?
Here is the link to the direct thread of mine-http://www.grandprixforums.net/f14/the-swap-pic-heavy-4210.html