The Ford F-series trucks with manual transmissions prior to the ZF-6, were known to occasionally develop high clutch pedal effort due to improper lubrication of the throw out bearing. Over time, the additional fulcrum effort against the clutch master cylinder would fatigue the firewall, until a crack developed. Often times this would go un-noticed, but since the driver would not be able to shift without grinding gears, a clutch job would be performed and this would remedy the high pedal effort part of the problem. A lot of the time, the new clutch would still under-perform, and owners would often chalk this up initially to air in the system. What a lot of people never do though is crawl under the dash and observe the firewall when the clutch is depressed. If it flexes or moves at all, you need this plate! This ingenious firewall stiffener, repairs the damage done by high pedal effort, and nullifies it as a future failure if it has not occurred. Even if you don't have a crack, you could put this in, and know that you will never have one. Sadly, this is the last one. Once sold, there are no more. Fits 1980 to 1994 Ford IDI trucks.