I used stock hangers from Toyota for my longer rear springs:



Put them wherever the marks line up. I like to measure the existing springs, front eye to center bolt and the new springs front-eye to center bolt and move the hanger forward the difference of those two measurements. This assumes you are happy with the rear axle position (i.e the tire is center in the wheel well opening). My 56" Alcans needed hangers 6.5" forward of stock on my '85. I first bolted them in place (drilled/tapped holes into the frame) and checked the spring fit. Had first tried 5.5" as I had heard someone else use, but moved them forward another inch after testing the axle location.