Assembled and installed oil cooler to the firewall. One mounting bolt was impossible to install due to limited access. Just couldn't get it to engage in the nut plate. Ended up removing the nut plate to be able to use a standard nut on the backside. Struggled with hole alignment and nut plate engagement on all holes. Hope I never have to take the oil cooler off. Added an angle from the firewall to the forward edge of the oil cooler to ensure support.