[Mimi N]

Are they 87 and the 91 interchangeable?
If not an 87, is there any other year that is interchangeable with a 91 Suburban without modifications? In other words, what are my options for a 91 suburban?

 

[hangtrojanover]

No, they are not interchangeable. To make the older one fit will require a bunch of mods to the suspension. I even think the wheel base is wider on the old ones. Stick with the new.