Update-
Well, I'm not sure why it didnt work for yours, being that we did the same thing, and mine came out almost perfect. The metal bumper support is slightly different like you said, being my '93 had a protrusion on the end that the '89 I got out of the junkyard yesterday (a few hours after I wrote my original post) didnt have, but I used my '93 foam, '93 bumper cover, and the junkyard '89 bumper support, worked most of the afternoon yesterday reinstalling the 1/4 panels and front end and today you cant tell it was ever in a wreck (minus a few minor scuffs on the bumper cover I havent had time to buff out yet) and its a solid as it ever was (before the wreck). Maybe the '91's different from the '93's underneath.........?
Oh well, to answer my own question, in my case at least, it worked fine.
