I wish I knew man- you could try Warehouse Services if you have one in the states(they supply Napa), junkyard fuse block if you can remove them, or maybe a gm dealership? I put in a hotwire kit for my fuel pump so i had an external relay, and i used inline glass fuses for my e-fans and water meth pump-could have put them in the uhfb but it was more convinient.
Back Alley Motorsports 98 GMC
-5.3l LM7 bored to 5.7l Thompson Motorsports -72mm T4 Magnum Turbo
-TU1 Custom Grind cam(spec speed.inc) -799 heads
-.660" Trick Flow dual valve springs -Forged Probe Pistons 3.902" flat top