Am I right in saying there is a type of long stud that isn't particularly good? From memory it's the type that has a flange around the point of the block deck, and when the studs are screwed down in - this flange seals (with an o ring) against a recess in the block surface. These are bad because you can get a false fastening as it can bottom out in the recess rather than the stud being fully home in the base of the block? I was told that the better type are the ones that have a groove around the stud at the block surface and an o ring sits in this groove and makes a friction seal against the sides of the hole drilled in the deck surface. Allowing the stud to fully sit home in the base of the block.

If anyone knows anymore the info would be good.

Correction : the second type don't have a groove at all. They are completely smooth all the way to the bottom and use a much bigger double 'lipped' o ring type seal where the stud goes through the block deck.. therefore no friction can be obtained at the block surface and correct torque figures obtained as the only contact point is in the base of the block. Has anyone had similar findings?