I got a set of 300hp injectors for my truck, & ordered an install kit from piers that had the new washers,(6 thick ones & 6 thinner ones) I've read on here that most people prefer the thin washers, then I got all the washers for the return lines, but no o-rings should the old o-rings be ok??? I assumed that the kit came with the rings, thought I needed them also?? just want to make sure before I install these things this evenin that the washers are all I need??? thanks, Dusty

 

now that I've opened up the install kit, I see that I have 3 different sets of washers???? one set is super thin, then the thickest set is probably 1/8 of an inch or so, then the middle set is about middle ways of the two?? not sure which set to use??? help please????? Dusty

 

Use the thinnest washers - it gets the spray closer to the bowl in the piston and helps a bit with smoke. As for the (rubber?) o-rings... I think you mean the sealing rings that go around the injector body/hold down nut. You can reuse the old ones. They're to keep water out & off of the body.