Looks like that is what I am going to have to do. I have one laying in the shop. I will clean it up and compare the two in the pinion bearing areas. My father inlaw had a set of 3.91 gears he thought were for a 489 and I started cleaning up my 489 before the gears got to me in the mail. I have already bought a install kit for the 489 as well. Looks like I am going to have to get a 742 install kit and a set of 489 gears and build both of the chunks.
