The total is 4", but the spring is only 2.5". The longer shackle (AOR) adds about 1.5" of lift. If you didn't replace the shackle, you would need a 4" spring, but may lose some flex movement with the stock shackle. I knew I would replace the shackle, so I only ordered my spring with 2.5" of lift over stock. I also figured this would give me some adjustment room if the spring lift was too high. The fit turned out to be perfect.

1997 T100 4x4 SR5 5spd