Guero is right about the bigger pump.
For an OEM application, would something like a Lightning use a 255 that might fit? Seems like 97-02's use GSS342's.
How about a Terminator pump?
I just looked that up. I dont know if the tanks and pump install kits differ a lot for trucks...... Double check the ratings for the application if you can somehow make that work.
Otherwise, I'd see if you can just special order the Walbro pump you need.
Good luck bud.