Steve,
My apologies for not responding to your request. I just did the same thing on my 3 when I switched from an angle drive with short cable to the long cable. I used an old thread that Randall told the correct way to route and you got it correct. Where did you get the small, half moon, clamp that holds the cable in front of the battery?> I'm temporarily using a white plastic TV cable clamp that is very ugly. My OD wires run through the top of the tunnel and have to be unplugged when the tunnel is removed, but it is not that difficult and hardly ever comes out. The folks at Mo-Ma who rebuilt and calibrated my speedo recommended going back to the original long cable. They said the angle drive and short cable has more stress and when the cable starts to go bad they can effect the speedo - mine was bouncing between 50 and 80 when driving 60. It is now smooth as silk!
Good luck!