I checked my book. for 69 chevelle it lists
1100834 37 amp
1100837 37 amp (says for AC also)
1100842 42 amp
1100843 61 amp (for AC)
1100849 optional 61 amp
From looking at my 69 olds chassis service manual, the generator that uses external regulator has the F and R terminals on back side of the generator; the built in regulator kind has a similar two wire connector, but it is on the top of the alternator body, with the terminals labelled 1 and 2, not F and R.