Are Champion plugs the recommended plug? What should the gap be? Are they pre gapped? 96 disco

 

Champion is what came from the factory.
They should be pre gapped.
There is a sticker under the hood with the plug gap printed on it.

 

Always check the gap on new plugs cause any one plug may have many applications.
Have you looked on the emisson sticker under the hood for the proper gap?
I am thinking there is a range, something like .35 to .42.
Have you replaced the plug wires yet? If not , consider a set of 8mm Magnecor or your new plugs won't help much.

 

I second the Magnecor.... Amazing results. My wife called me on the freeway while she was driving it telling me how much of a difference it made when she punched the throttle.

Jason