I've got 3 jag xj6 rears in my shop, and and an 85 front suspension.. I ordered the T bucket prints from CCR in southern calif. they give you all the dimensions and full size paterns for the whole t bucket for 20 bucks, the jag rear end print is 5 bucks, a real deal. I used to mock up a chassis using 2x4's before i cut steel but the CCR plans has ever thing fitting first time. The only thing is that to tap out the 7/8 dom tubing without a lathe I cut the rods 1 inch longer than the spec, then start drilling with the smallest drill bit that will remove metal using a milwaukee right angle 1/2 inch electricians drill, slow and lots of torque. I keeping changing bits until I get to the 17/32 ( I think). The last step before using the 5/8 tap is to use a 5/8 drill and drill out 1 inch deep. this makes the tap align and centered, no wobbeling. When you tap as deep as you can go cut off that 1 inch extra length then check with the drill bit and if necessary drill the required depth then finish tapping.