Book shows no 13 no dash issue. 13-1 is first issue,1974, 3" rd. btt.,4" sq.btt., P & R.
13-2, 1977, same but change gas ring from yoke to cylinder.
13-3, 1982 same but eliminate P & R.
13-4, 1988 to end (1999)same with new yoke retention, radius stud pkg., floating hand/ hammer nose bushing...