I am also retired and am building a Ford based Lotus 7 since cost does matter. Here is a good refference file:///c:/Documents%20and%20Settings/~/Desktop/7/rear%20suspension/irs.html
What I have wound up with is 92 Lincoln Mk VIII diff housing, 03 Explorer rear cover this allows 4 point mounting and eliminates a known weak point, the rear mount. The internals are standard 8.8, almost, I intend to use the Torsen T2(OEM) carrier since it has spring preload so if a wheel gets off the ground it won't smoke when it comes back to ground it is also 31 spline. There is a problem with the Torsen T2(OEM) in that it is not machined for the IRS stub axles, my hope is to be able to remachine the C clip groove to allow for this problem. What I have found in an attempt to convert to 5 on 4.5 bolt pattern is that the Cobra hub can be pressed into the rear knuckle, 04 4x4 Escape front rotor are the right size to allow the original MN12 rear caliper to be used. The front knuckles can be used by cutting the top part of the knuckle off at the sway bar mount and suing that for the upper BJ. These can be converted to 5 on 4.5 by using 99 Mustang GT hubs and rotors. I am going a step further to lighten unsprung weight by performing more surgery on the knuckle and adapting 99 to 03 GT aluminum PBR calipers, this setup weighs 40 lb for knuckle and brakes though I think there is a bit more I can cut off the knuckle to reduce weight further. Hope this helps feel free to pm if more info needed I will try to help.
00 Cobra R, 03 explorer, 92 MK VIII with explorer rear cover
