Westside lifting is designed to build strength. If you lift as they recommend (and eat enough) you should gain strength.
As for your 1RM percentages, I do not know of any set percentages that would apply. Hopefully someone else on the board does. Based on my own training, I would roughly suggest something around:
3RM = 90-95%
5RM = 80-85%
7RM = 75-80%
The best way to calculate your rep maxes is merely to go ahead and do them.