If your wanting to replace the injector assembly, I recommend upgrading to the MFI. It's cheaper and more reliable. The parts can be purchased from
www.GMPartsDirect.com for less than $200. Here's a TSB that covers the installation (Page 9, I think).
http://www.myfilehut.com/userfiles/1...20TO%20MFI.pdf
All the part numbers are at the bottom. The FPR is part of the new assembly and included in the price.
Any reason that you're wanting to replace yours? Other than clogged poppit valves, they rarely go bad on the 96+ engines.