I agree 1.7 amps is safe, 1C is a lipo term normally. Simply charge it and let it peak, watching for excess heat. Seeing 7v is normal, 6v is the nominal voltage and is not the same as a pack that is full.

1C refers to mah/1000 and won't exactly mean charging at 1C will result in a full charge after 1 hour, charge time can vary...