Anybody built their own harness?

[LS short box]

On my 68 with the LS swap I didn't use the stock fuse block hole. I patched it up and made a new hole with a grommet behind the the inner wheel well. There is not that many wires that run forward and back for the chassis.
I moved the Painless fuse block back a bit with a couple angle brackets fastened it to the side panel near the vent door.
In regards to wire length I don't recall having any issues length wise. GM wire color really didn't matter to me. You could check against a stock wiring diagram.
I love hiding wires.
Couple of pics.