Narrowing 8 3/4 details

All above info good...when I did my rear end shortening I used a trk housing,cut off the ends at the weld joint with a 14'' cut-off saw with metal blade like muffler shops use,I did this by removing all the 3rd member studs[and axle end studs] and laying it face down on some short 2x12's to match level of saw,at this point you dont have to worry about squaring the end tubes yet as you are cutting following the weld joint,I then took the cut off ends to a mach shop and had them turn the centers back out to tube size which if I remember right was 3'',and about 3/4'' depth so they could be slid over finished tube and welded,you will have to grind/sand the tube ends to clean them up and fitament and you want to test fit ends to tubes and you want them tight,I had a new set of ends for this project but I didnt like the design[butt joint weld ons] as to why I reused the originals turned down to fit over the tubes,made it alot easier to fit and square up and weld...I did not use a jig,just a pair of trk jack stands,3 small magnetic levels,one for middle of each tube and one for pinion area of 3rd member,a 2' square,some welding clamps and some blocks of wood to support the 3rd member when its all mocked up to keep it from rolling,also mocked it all up including the axles,3rd member and when I was satisfied with it I tac welded at 12-6-3-9o'clock positions then rechecked and welded with it all together after rechecking 99 times...lol...as to the spring perches I mocked it all up in car and set desired pinion angle and then tac welded.rechecked and then removed and done the final weld,sure I'm missing something here but this the basic rundown..this was not without its problems I ruined 2 housings[warped] before I got it right just my 2 cents worth...