Ok here you go. The springs on my old Speedster one(on the left) measures 50mm with a wire diameter of 1.26mm, that is exactly the same as the new ones I have (on teh right). The one in my 96 XP has a spring length of 44mm with a wire diameter of 1.26mm. So the ski has a different length than the boats do, I guess for 95 and 96.
Now you can visually see a difference in the top caps, the two bump outs with the holes. There is also a difference in the internal cap that the bellow clamps to, it's more like the RAVE cap on the guillotine valves on the engine are. Also, the fitting on the bottom that threads into the water box is different. The old one has a 3mm thru hole where the new ones have a 4.5mm thru hole.
As far as the internal fitment, it's what I refer to as B.A.T.--Balls Azz Tight or a Honeymoon fit.
The main lower base is the same part# on all of them. So if you were to put one of these on a ski, I would verify that the brass fitting is either the same OR you reuse your old one, verify the spring is the same or reuse your old one. Or just install the new one as is, since they are like that on all the 97+ skis/boats and probably wouldn't make a difference.
So on a 96 XP it's part# 274000316 which lists for $222.49 and on the 97+ skis/boats it's 276000134 which will set you back $113.49, we paid $90.79 each. So you can save yourself $131.70 by getting the later unit and just do the part swap (spring and fitting) yourself.