Hi Jeff,

If you're wanting just basic 2d lines to check the fit between parts then I would suggest drawing a simple planar surface as your cutting plane 'Draw Solid>Plane' and using 'Construct>Curve>Isect' to create section lines, after doing that you can also select the plane and curves produced and enable history update 'Edit>History>Enable history update' in doing that you can move the cutting plane and the section curves will update accordingly.

Cheers