I would say from your description your current string maybe a endless loop string. If the loop holes are wrapped in serving thread and no twist in the string it's a endless loop. Most of the older Bear bows take about a 4" shorter string, if the string on the bow you have now is at a brace height you are comfortable with, you can take the string off the bow and measure it's whole length from end of one loop to the other, and go with that length.
Do not put fast flite material strings on that bow, it won't last very long if you do. Use B50 or B500 string material (Dacron). For that bow also, stay away from D97, TS+, 450+, 452, 8125, fast flite, fast flite plus, excel, or anything else that says pretty much low stretch, or has HMPE written on it.