New GM single screw. This screw holds the distributor plenum cover to the plenum on Tuned Port Injection engines.  This has a torx head with a built in centering washer.  This ONLY works with the factory plastic covers! Screws are sold individually!  Fits the following:

85-92 TPI Camaro
85-92 TPI Firebird/Trans Am

NOTE : Your plenum threads must be in original condition for these to work, meaning if someone put the wrong screw in your plenum and or damaged the original thread, these will not work.