Even if you took all the correct measurements your still going to have to fine tune with the new string. Depending on the twist in the string. There are so many little things when you do a wholesale change out. If your nock points even an 1/8" off or peep is higher or lower than the original location by an 1/8" or more that will give you a huge down range difference. I would suggest a quick paper tune which i asssume would be good still. Then simply resighting your bow in if you are saitsfied with your anchor point and peep height. That why your not relying on whats was but what is your bow set up. Good luck.