I would think your axles are twisted like pettyblu's pictures. You already have the center section. The cheapest way out for you is the MO875 Like Turbodart68 is recommending.
I am in the middle of building a Ford 9" for mine and Triangulated 4 Link. I am swapping out the 8 3/4 with basically the same set up.
Labor to shorten etc is my own.
Paid $160.00 for the complete 9" rear end.
$60.00 for new big ford housing ends
$45.00 Back Brace
$45.00 Large Aluminum fill & Drain Plug assy
$80.00 for sheet of .250 Chromoly
Total to shorten with new tabs built by me...... $390.00
$1000.00 for New Nodular Drop out with 35 Spline Spool, 3.50 Gears, 1350 Billet Pinion Yoke, Daytona Pinion Support.
New 35 Spline Axles $350.00
This set up is good for 1200+HP.
Here is what I started with and where it is as of today.