1947 Imperial and Chrysler Service Book – Cam Ground Piston
Modern pistons have much less contact with the cylinder wall.  The part Chrysler has &quot;cam ground&quot; is no longer even part of the piston -- it&#x27;s missing!  The main job of the fit is the rings, not the piston.  Right, for the &quot;thrust&quot; parts, they are still there and much thicker than what Chrysler was showing.<p>There&#x27;s much more now, e.g., titanium connecting rods.