groove for an o-ring

In the toolbox there is a feature for cutting a groove for ano-ring. This gives you certain options for certain standards. WhenI called up the groove for BS 4518 - 0795-30 static facing sealo-ring it gives me an outside diameter of 88mm and an insidediameter of 80mm, this standard refers to a situation where thereis external pressure. The situation for an internal pressure whichI need is 77mm and 85mm but this option is not available so I haveto change the dimensions of the first. This is made all the moredifficult as the is no automatic dimensions. This would be a nicefeature to add because the dimensions and tolerances of thestandards are standard. I am using SW2007 so maybe this has beenchanged already or am I missing something. I have a few imagesattached to explain.

Thanks
SolidworksParts And Features