I temporarily installed the engine mount using 3/16" nuts and bolts. The undersized pilot holes are all within the confines of the 3/8" final hole size. One at a time I inserted a 3/8" bolt with torque seal dabbed on the end and pushed it through the engine mount holes to mark their locations onto the firewall. I will have to move the pilot holes over a bit and drill to 3/8" final size.
