XJ40 steering rack/Mk2

Can anyone advise on the improvement of a modern xj40 steering rack does to the Mk2?
I see many have been done, just wonder what the comparison is from stock to rack and pinion. Approved type mod, or?
Does it take a new steering column to do the mod?
Any advice appreciated.
Thanks,
John

take a look at the MC Wilkinson web site. the brackets to mount the rack (and the associated engineering) are key parts.
the powered rack transforms the car but…its a personal choice if this is an improvement.

1967 mkII/340 I put a steering rack and pinion in my Jag a few years ago and I love it. I went from the stock original power steering setup (broken and unable to get repair parts) to a manual steering box (it drove like a truck, very hard) to the rack and pinion which was purchased from XK UnLimited , SLO California. I installed it myself and not to difficult. It was not necessary to change steering column. Check historical posting some pictures of the set up are posted.
Richard O

My MK2 has a close ration box just over 3 1/2 turns lock to lock , yes it’s heavy on the steering , but oh what a pleasure around the bends !!
As for fitting a XJ40 steering rack , is that not old technology now , with electric steering readily available !

I replaced my old worn out box with the XK’s kit and it was easy to do and works well. Very stable in a straight line and pretty light steering feel. That said, not sure if my rack is now years old and gotten a bit sloppy or I’m driving the car with more gusto but I’m debating going to the close ratio box mentioned above for more precise performance. It’s a bit vague in turns especially at speed.

From my steering rack conversion on my 3.8S there are upsides and downsides to this conversion. But I am not going back to the factory power steering box set up. The upsides are, great steering precision, no steering leaks, operates fine on the original generator mounted pump. The lower column can be shortened and different U joints fitted and the splines are compatible. The downsides: lack of Ackermann effect, resulting in a reduced turning circle, tire scrubbing on sharp turns which results in premature front tire edge wear. And FYI, most of the mounting brackets I have seen work with an XJS or XJ6 series I to III rack, not the type fitted to the XJ40. My car uses the later XJS ZF rack for it greater durability.