Battery in Trunk Wiring That Exceeds NHRA Requirements
Put a fuse in the line from ford relay to the cutoff or the line going forward. Just in case something goes wrong up front.
You already have the cables made up, I wouldn't bother making a set of 4ga to replace it. I always chuckle at guys that aren't index racing in eliminator classes complaining about the extra cable. It's under 5 pounds in most every case running things my way. Go on a diet if the 5 pounds is killing your car, and your health would likely be improved as a side benefit. :lol: One complainer was 300+ back years ago... ironically funny to me.
No sweat, just follow the schematic. You generally can't mix and match approaches on this stuff.