Hey, Jack
Check out my diagram again:
[img]
http://alanhorvath.com/54chevy/chevypics/wiring_1.jpg[/img]
The wire that goes to your fuse-box doesn't go to a fuse ... it powers everything; it powers the fuse-box itself.
I agree, the Kit from Madd Electric is not only a good deal, but it's the best way to power everything up (see my diagram above) ... by installing the terminal blocks and powering things from there, your truck gets better voltage and better performance all around!