Unsure if there is a difference, these seats were manual types, not electric.
Fitting Jaguar XJS Seats proved to be very simple once I had worked out the position for the seat and where to drill the holes. This assumes that you have the runners etc complete. Fitting as below is recommended, I tried doing the front holes first and it proved to be difficult doing the back holes and I had to remove all I had done and start again. The seats were non electric. Start by drilling a hole 3 inches from the rear end of each runner.
This will be further in than the existing mounting hole. Make sure that the runners are as far back as possible. Place the seat in position in the Car as close to the center console as possible and drill two holes in the floor just under 1 inch forward from where the floor drops down to the rear footwell. These holes are where the two bolts will go from the two holes you drilled in the Seat runner so you will need to align. You will find that the bolts will now go through the floor and be between the Center Chassis outrigger and the rear footwell edge so easy to get at. Once the rear bolts are fitted slide the seat rearward and you will now be able to get at the front holes in the seat runner (The existing mounting holes in the XJS seat runners). Drill through the floor using the front holes as a guide. You should be able to get the drill in position without removing the Seat. Once holes drilled fit bolts using a spacer about half inch thick between the seat runner and the floor. The reason for the spacers is to allow the bar across the front of the seat not to be held up by the floor. If no spacers are used there is a real possibility that when you adjust the seat forwards or backwards the bar will not fully go back down and the seat will slide during braking etc. The spacers need to be strong enough to allow for the seat to be held safely. At the present time ( 4th September 2006 ) I am going to try some spacers at the rear bolts as the tilt of the seats seem to far back and it would be something to try. Check back soon to see if the seats are better not being tilted back so far.
Addition March 2007
After a few months I though there could be improvements. While all was OK I thought it could be possible to get the seats closer to the center transmission tunnel. The main reason was the Top of the seat was very close the the seat belt mounting area (The area on the door pillar where the seat belt goes over your shoulder). This was not a big problem but made putting on the Seat belt a bit awkward. The seat mountings as fitted to the XJS seats did not allow the seats to be any closer to the transmission tunnel so I looked at the possibility of fitting the XJS seats to the original Scimitar seat runners as these runners are narrower than the runners fitted to the XJS seats. The XJS runners are removed by sliding the seat as far forward as possible and undoing the bolt at each side, then slide the seat as far back as possible and remove the other two bolts. The next bit sounds a bit of a bodge but if you try it it is quite acceptable. One the front of the Scimitar seat runners are two brackets that had a bolt through to attach the seats, these are what the Scimitar seats pivoted on. Bend the outer ones each side away from the middle untill they are flat, the inner ones bend to the middle until they are flat against angled crossmember. If you now place these runners on the bottom of the XJS seats as far forward as possible you will find that the holes on the brackets that you bent will be aligned on a bit welded to the XJS seat frame ( Where the frame of the seats bends from the front to the sides ). Ensure that the runners are as far forward as possible and level along the sides. When you get the runners in the correct position you will find that you will be able to drill two holes in the XJS seats ( Not the seat frames but the metal plates welded onto the frames ). You will need to peel back some of the covering to get at these metal plates, easy to do and replace, just remove some of the clips. Once the holes have been drilled attached with a couple of nuts and bolts. Once this is done you will need to make two plates for the rear of the seats. These plates will screw onto the edge of the XJS seats and screw onto the Scimitar runners at the rear, there is a wide bit on the runners. This was where the Scimitar seats rested on. The rear plates will need to be quite strong as they will need to take the weight of whoever is sitting on the seats. Once all this is done fit as explained above making sure that the seats are as close to the transmission tunnel as possible and the rear mounting holes about 1 1/2 inches forward where this area drops down to the rear footwell. The reason for this is the bolts, when they go through the floor will need to be just behind the center chassis outrigger. I found that I did not need any spacers on the front of the seats but the same size spacers as when fitting the XJS seats with there original runners. One of the reasons for keeping these spacers at the rear was if the seat was pushed to the rear the seat back adjuster lever fowled on the bottom edge where the door closed. Once all of this was done I found that I gained about 1 1/2 inches away from the top seat belt mount. Not much I know but it makes it easier to pull the seat belt.