The gasket is determined by piston protrusion and not whether or not the head has been shaved.
Andrew
Okay thanks for the reply but can u explain a bit more?
The pistons protrude above the top of the block in the 1.6 engine. The amount of protrusion dictates the thickness of the head gasket.
The thickness of a head gasket is identified by the number of notches on the gasket. The notches are located about the center edge of the gasket. Looking from the front of the car, the notches can be seen on the gasket edge that sticks out from under the head next to the oil drain back (round part of block and head).
Check the Bentley manual, there is a good explanation of the gasket thickness and piston protrusion.
Like others have said, generally speaking, cracks between the valve seats is not a problem.
And, typically, if you can put a 4 thousandths feeler guage under a straight edge laying across the head, it is questionable whether or not a new head gasket will hold very long.
If you have the head off, check the clearnace, if its over the 0.004, then have it milled.
Side note: I have used fine steel wool and 600 sand paper with water to clean the surface of the diesel head.