Perhaps cowls are different now but I had to put a thick stainless steel strike plate inside my cowl to avoid cowl damage from the pulley after I saw scuff marks adjacent to the pulley. I looked at a friend's new O-320 engine installation in his RV-6A and told him that he should be concerned about the close proximity of the alternator pulley to the inner cowl surface. He completed the installation and flew as is. The pulley cut a hole through the cowl in the first few hours. It's OK statically but during start up and shut down the engine moves around quite a bit. Some people have fabricated blister fairings to provide the necessary clearance. My first stainless steel source was the thin firewall material cutout for the oil filter and prop governer clearance but it was too thin. The one that has worked for a few years now is a section of a broad butter knife blade glued inplace with structural adhesive.
