Narrowing Costs

I narrow 9 1/4 rears for A-bodies. 9 1/4 housing tubes come out of the center at 3 1/2" and taper down to 3". Where the taper is located will allow/not allow the housing to be used, because of the spring perch mounting. I use housings out of older C-bodies or 70's trucks because the taper is closer to the center. I use 8 3/4/Dana ends from Moser, custom Moser 31 spline axles and Green bearings. I use all the Dakota/Durango/Truck 9 1/4 internals in the older housings with no problems. I can answer any of your 9 1/4 questions.