Installing new injectors copper washer thickness?
 

I have new Bosch injectors to install. I got an injector installation kit off EBay, it has 3 different size copper washers for new install. Kit states to match your old washers to same size thickness as the old, but the old copper washers for the old injectors are thicker than any in the install kit. Wondering what every one that has installed new injectors or cleaned up their old ones has done. The only immediate thing is use the thickest washers and the smallest washers and stack them, but I'm thinking it's not a good idea. Input appreciated.