Best way would be to make a drawing with marks on a line from the a-arm pivot point to the shock mount, the center of the spring perch, and the center of the tire. Then measure each gap between the spring coils and add it up, and also measure the amount of shock shaft showing. Do a little math to determine how far up the tire would need to move to bottom the spring or shock out, the smaller of those 2 will be your answer.
Mike