Below is the verbage...the second paragraph mentions trucks, I want to know about 4Runners
Rear Suspension Instructions
All Pro's rear 56" long 4, 5 and 6" lift springs are designed to be used on 1979 and later Toyota Pickup's and 4Runner's. When installing these springs it is possible to keep the axle location as it was or to move the axle forward or backwards depending where you mount the spring hangers. For example it is very common to move the axle back one inch to allow for a better fit of the tire in the fender well.
When installing the 56" long rear springs on 1979 - 1988 trucks, the rear shackle hanger will need to be cut off with a dye grinder and moved back 1.5-2.5" (depending on desired shackle angle) and reattached. The front spring hangers can not be reused after cutting them off so we recommend our heavy duty spring hangers.