Bucket seat subframes

[4WayDiablo]

So I've got hold of some seats and subframes and I'm trying to get them in but it doesn't seem to fit?
Here is the trouble I'm having the plate that goes on the side of the car does not seem to be long enough?
   
And
   

Now I'm not being thick and trying to attatxh them in the wrong place?
They are supposed to go where the original seats bolt in?
And yes 3dr to 3 dr