The post 77 Archers all had 62" pitch props. The earlier ones had 60".
This is the entry from the FAA TCDS:
Propeller and Propeller Limits Sensenich 76EM8S5.
For S/N 28-7690001 through 28-7790607: Static r.p.m. at maximum permissible throttle setting, not over 2425 r.p.m., not under 2325 r.p.m. at sea level, ISA conditions. (Reference aircraft Maintenance Manual for test procedure to determine approved static r.p.m. under nonstandard conditions.) No additional tolerance permitted. Diameter: Not over or under 76".
For S/N 28-7890001 through 28-8690056; 28-8690061; 28-8690062; and 2890001 through 2890205: Static r.p.m. at maximum permissible throttle setting, not over 2340 r.p.m., not under 2240 r.p.m. at sea level, ISA conditions. (Reference aircraft Maintenance Manual for test procedure to determine approved static r.p.m. under nonstandard conditions.) No additional tolerance permitted. Diameter: Not over or under 76".
My aircraft is 7790402 so I am in the first category but as you can see there is no mention of what pitch the prop should be.