67 Shelby S/W underdash gauges

There were two or three different types of wiring from the gauges to the junction block, along with two different junction blocks. What is your car's number (last 4 digits of the vin) so we can zero in on the correct way.

 

You would have the harness that is pre-packaged and comes wrapped in an enclosing jacket. Late-type juction block. This might be available from NPD, but, I did not look in their catalog.
I'm not sure on the routing but I bet somebody here with a late car would have a photo.
According to the Shelby Assembly manual that you can buy from Branda, the harness comes out of the firewall in the same hole as the choke cable, runs along the right side leg of the export brace, then to the junction block mounted near the solenoid

 

I am just a young pup learning and dont know if its a big deal or not, but i think the choke cable came out of a hole of its own and the gauge harness aswell as the oil pressure line came out of a seperate hole together.

 

Well, I own a very early car, and, all that stuff comes out of the same hole in the firewall. But, any time now someone with a late car will give you the correct answer.

 

There probably is some hospital supply tool for this but, I took a metal wire coat hanger, bent it into an 'L" shape with about 3/4" to one side, glued two turns of cloth to it. I slipped it into the hole for the light. It worked but could not reach everwhere. Most of my interior glass mess was just inside the light hole. Hope that helps.