Before you decide one way or the other on reusing the current 8 3/4 check the housing for straightness now and then decide
My Duster had a bunch of mid to low 10. second runs on it when it bent the heck out of the housing enough to break the ladder bar mounts welds loose from the housing
Luckily that happened on the starting line and not going into 3rd gear It may have been bent a little to start with after having it narrowed
I have someone help me check the housings by using two carpenter square and measure off of the axle flanges or the rear end bearing ends 14 to 16 inches out from the center of the axle to the front and rear and up and down as much as possible, if it varies more than .125,1/8 inch or more, between the front and rear or top and bottom measurments it is bent more than it should be
Let us know what you find and decide to do