Mounts are all new, as I was there, and easy to do at this point.
Funny thing, all is in line with the mount brackets on the body. Fits perfectly. Tighten the bolts and it all fits.
Got me baffled.
Actually have a 91 also, did the same extra swap,,,OE to Oe,,and no problems. Both 5 speeds. It's my sons. So he is coming over and we are dismantling his and taking some measurements. It's all that I know to do.