The wood or sheetmetal type screws aren't as strong as the typical hobby store machine screws. The heads have been known to pop off the wood screws from vibration, and twist off from too much torque. For most applications they work great. I would give them a try, just keep an eye on them . Make sure that the mount beams are absolutely flat , so your high performance engine doesn't get tweaked when you clamp it down. Attaching a perfectly square mount to a warped firewall will leave the engine mounting beams out of whack. The act of pilot drilling, and running the screws in to the glass filled nylon raises little "volcanos, that you will need to knock back down before you clamp the engine down to the mount