This one has been on the road for five years or so and has done great. Same XJ6 as yours and entire cradle was used on rear but the lower frame flanges were just bent down rather than notched. Center section on a Jag is a Dana so limited slip and cruising friendly gears were used.
[img]https://s14.postimg.org/8pk5twtt9/Chuck_s_55_006.jpg[/img]
[img]https://s14.postimg.org/cohdctarh/Chuck_s_55_007.jpg[/img]

Evan