Considering the complexities of the subject project, I’m thinking about building up a complete front subframe BEFORE dropping the one in the car. Part of the rationale is to then refurbish the old subframe and suspension components for next time. Has anyone else thought to do this? If so, maybe there’s a completely refurbished XJ81 front end taking up space in someone’s garage that I might wrestle away in exchange for a big check? 
Would it be cheaper to just find another XJ40… nice low milage well cared for…or best you can get…then use the front or parts as and when needed
Cheaper? Maybe…but then I’ve got to take apart two cars and ultimately I’ll still have used parts on mine. Still…I might look for one to test that.
I have a 94 XJ12 I am more than willing to sell the entire front suspension unit. It is in good trim, but I would think bushings, and such could use refreshing along with the steering rack. What part of the US are you located in?
Kenosha, Wisconsin.
John 262-498-3640
I am located just South of Pittsburgh, PA. If you are interested just let me know.
Stephen 412-853-1612