I have several matched pairs of 550 and 850cc injectors. These were just rebuilt. They have all new pintle caps, viton o-rings, and screens. The viton o-rings are much more durable and fuel-resistant that the original rubber ones. I have flow test numbers as well. I am asking $135 shipped a pair, priority mail. No turn-around time. Guaranteed not to leak. If they leak, you get a refund or a replacment set. If you give me a pair of usable injectors back I will refund $30.