Remove upper and lower cowl. Using a pneumatic riveter with a very narrow jaw. finish riveting the horizontal cowl lower attach plates for rivets that could not be reached with a stock riveter due to the close clearance between the firewall attach point and the engine mount. Rivet Skybolt receptacles to the flanges on the lower cowl at the vertical firewall joint on the right and left sides. Drill the cowl for grommets, attach grommets, and insert studs. Fit cowl lower and upper cowl. Adjust stud depth for a few studs that were not set for the correct depth. Note the clearance between the lower cowl and the filter air box snorkel. I believe this location is ready for installation of rubber baffling.