I have an 84 500 Sel and a 87 560 Sel . Are these considered "interference"engines should a timing chain break?

Also I am rebuilding the front suspension on the 84 (W126). The replacement control braket bushings I understand are one for front and one for the back and are differnt sizes. I read somwhere the larger one should have the " two square edges" as the original. The ones I bought are both round but are the correct sizes. Any thoughts appreciated.


God Bless
John