I looked into it earlier, the exploders and expeditions went to independent 8.8's. i googled explorer irs 8.8 and some people are building some nice setups using them. The cobra setup would be nice for handling but would lack alot for anything off road.
Hmm, I did not know that and since my ex-wife drove an expedition I should have. Good to know!
I will have to look into this since I want to do an explorer rear disc brake upgrade anyway and the idea of an IRS is interesting.
Just don't get all the naysayers about the TTB's?
I've owned several vehicles with TTB and I have never had any problems with any of them.
It seems sometimes there is a forum wide mindset that SAS good, TTB bad group think going on without thinking that not everyone plans to use their Bronco for rock crawling or other type of off-road driving where the extreme flex is needed.
Honestly IMO that is the only area where the SAS is superior.
For snow, sand, desert or general off roading I think the TTB is better.
Not everyone wants their Bronco to just be a play toy.
Personally I want mine to be good at all off-road situations as it is my go anywhere anytime I need to get somewhere regardless of the situation or driving conditions.
So for the O.P. who is interested in a rear TTB, if it fits for what you are trying to build than go for it. Just don't get mind locked onto a rear TTB if another replacement will work better, be stronger and/or be more cost effective and easier to build.