access fuel tank pickup screen?lower tank or drill hole in floor?

[welcomehome]

i have a model 3800, year 2000 bluebird handibus on a t444e international diesel engine. the body number is L045790. i am trying to figure out if there are filters on the fuel pickup inside the tank, and what is the method to remove the fuel pickup out of the tank since i see no bolts.
im investigating a possible low power situation. after about 4 days of being parked on asphalt working on a rear wheel, i cranked her up and let her sit and idle about ten minutes to warm up. outside temps were warm, in the mid 60s. i then drove her forward about 15 feet and then reversed about 45 feet, which left my back wheels on my friends grassy backyard. i put her back in drive and proceeded to attempt to pull forward so that the back wheels would rest on the asphalt. i got no response from the throttle, no engine revving, and no moving forward. i fought the urge to turn her off and crank her back up to see if there would be a different result knowing that it wouldnt address the possible issue. i let her sit there and idle about another 10 mins and tried to pull forward again. this time she very slowly creeped forward off of the grass; almost like she was waking up. the only other time this happened was several months ago in his backyard as well. ive recently changed a failing fuel pump in the valley, the fuel filter, and cleaned out the small fuelfilter prescreen right next to the fuel filter. also changed all the short rubber pieces under the hood. i heard of the possibility of two screens on the fuel pickup unit inside the tank that sometimes gets clogged.
i looked in the hole in my floor that is above the fuel tank and found that it provides access to the fuel gauge unit but is about 4 inches too far forward to provide access to the fuel pickup unit.
since i see no bolts on top of the unit, i wonder if it is even designed to be removed? it looks like my options are to lower the fuel tank, or to cut a new hole in my floor to achieve access to the pickup unit.
any of you have advice or experience about this? thank u.

[welcomehome]

as it turns out, i had no internal screens inside my fuel tank or pickup tube. i dropped it and took it apart, but found none. i guess the tales of an internal fuel tank screen apply to the ford powerstroke models only, or at least , not in my t444e. i had previously cleaned the fuel filter prescreen located by the fuel filter.
my low power issue i believe was related to not letting her warm up long enough combined with being low on tranny fluid.