The adjuster (if you are referring to item 19 in the below figure) is a special screw and the thread and strength class are not listed in the factory parts catalog only the part number which is: 911.341.115.00. This part was used on most 911's from at least 1972 (probably from 1969) through 1989 and also on the 914's. Pelican shows it to be available at US$34.75 each (ouch!). I measured said adjuster screw on my 1976 911S and it appears to have an M12x1.5 thread; there is an approximately 3 mm long dog (a reduced diameter unthreaded portion) at the tip; about 80mm of thread length and then a small external hex head, 11 mm across the flats (an 11 mm spanner or socket fits). Jim
