I left the grounds to last, and just routed them to the nearest grounding post...
of which there is only 3: Drivers side transmission mount, pedal box under the dash, and the side of the battery mount.
My frame was one of the last ones to have a tunnel ground post, but I just skipped using it.
It really doesn't matter where a ground goes, as long as it has a good connection to the frame... anywhere works!
Keep what you have, and debug the positive wires, don't fret about the grounds, they just all connect together.