This is from another forum.
Number 8 had a TSB for the noise being a dead headed fuel system, they installed an AE code injector in #8 which is also called a long lead injectors as it is mechanically tuned to deliver a longer lead time to allow for less cackle. Technically you can run either, I run AD's which are 1-7's. But I also have a Fuel Rail Crossover to eliminate the dead head issues.