'86 420SEL: Injector-Holder O-Rings
 

As part of my timing-chain replacement project, I am replacing brittle air hoses and injector holders. The plastic injector holders I bought have the o-ring already in place; these are black, and those I removed from the engine are green. Typically green O-rings are made of Viton, a better material than buna, the material for most black o-rings. Should I get the green ones, or are the black ones I have now OK?
I am having a little trouble removing the #1 spark plug to get the #1 cylinder on TDC compression to reinstall the distributer. I am soaking it with PB Blaster and moving it back and forth a little. I don't need more trouble ;-)
Thanks, Randy