ok, here are the two types i have:
4 spray hole - 078133551E
2 spray hole - 078133551N
My Audi is a '94 90 quattro w/ an AAH engine. Also, almost all of my o-rings on both injector sets are in great shape. Can I re-use them?

on your engine.

The O-rings, if it were my engine, I would not reuse, as they seal gasoline. You dont want gas leaking on your engine. ;O)

I'll get new gaskets. Your right... i definately don't want gas leaking !!