I've got a 97 GMC Sonoma 4.3L - and a couple months ago it felt like someone pinched the fuel line off if I went WOT. It simply hit a wall around 3k rpm. So a buddy and myself changed the fuel filter. HUGE difference! Problem solved. Or so I thought.
The past 2-3 weeks, the truck has taken 5-10 tries to start from cold. Key on, hear the pump prime, crank - nothin. Rinse, wash, repeat. Then finally it'd start up and run just fine until it sat for a few hours, then I'd have to go through the embarrassing ritual again. Finally got out my fuel pressure gauge, and engine off, key on, it tested at 50psi. Same thing when it was running at idle. It would increase with RPM, but topped out around 62psi WOT @ 5k. Figured this is on the low side pressure-wise, so I ordered a pump assembly. Hopefully that'll solve the problem.
At any rate, I've read about removing the bed to install the pump from the top. Also the (maybe) more traditional method of dropping the tank. Both of which seem fairly easy, but would take patience - which is in short supply as of late. So I decided to cut an access panel in the bed. Took some measurements from underneath, marked it in the bed, and got out the 4½" grinder w/ a metal cutting blade. Before starting, I put a small piece of wood on top of the tank to cover the pump and hoses, just in case the blade went through the bed too easily. All went well. Took about 20 minutes. I'm still waiting on the pump assembly to arrive, but I'm ready for it now!
The access panel is 10" wide, 8" long, and 15" out from the driver side bed wall. It's also 5" away from the cab side of the bed. This allowed the cuts not to damage the structural support "beams" under the bed itself.
There's a pic attached with measurements. Hopefully this helps someone else, because I was hard pressed to find any specific info about this particular method of FP access other than "I cut a hole in the bed of my truck."