Installed additional passthrough. Defined position for Main Passthrough and ANL / SHUNT. Decided to trim the fiberfrax to allow direct riveting of oil cooler mount to the firewall. Trimmed fiberfrax to allow direct contact of engine mount to the firewall. Fiberfrax should not be sandwiched between riveted items as with vibration the fiberfrax loosen up and rivets are not holding tight.