I recently completed a throttle cable conversion on my 77 280Z. Combined with my new throttle body, it's smooth as can be. Without going into all the gory details, here's some pics.
Here's an overview pic. Cable come through the bulkhead and swerves a soft S-bend towards the master cylinders. This allows some slack in the cable to account for engine movement while running. It also allows clearance for the EGR valve if you are running one. My PO removed mine, but I may reinstall at some point so I wanted the cable to clear. Top level overview:
Here's the bulkhead passthrough. I made a threaded adapter and sealing nut on the lathe. The flats allow me to get wrenches on the passthrough from the engine compartment so I don't have to use tools up under the dash. This is the second passthrough I made... First one had the tightening nut on the other side under the dash. It worked fine, but was a real PITA to tighten with wrenches up under there. So I spun it around and made another one with the installation direction reversed:. Don't mind the loose A/C grommet:
Here's another pic of the firewall passthrough. In this pic, you can see how the cable is held into the passthrough. The metal ring is crimped into a hex and that clamps down on the cable sheath holding it in place. Since the sheath is pretty much always in compression, it doesn't have to be a hard lock, but it's nice that the sheath is a decent friction fit into the passthrough. Yes, that's a cable RG-6 crimp tool used for cable TV and Ethernet. I got lucky and it works great for what I was doing:
Under the dash, I converted over to a different connection design on the pedal. I purchased an already messed up pedal from someone with a failed cable conversion. He had already removed the original ball stud, so I drilled the hole out to the correct size to tap with threads and ran a tap through. I also made an "L" bracket adapter to attach to a Honda Civic throttle cable. I ground a little off the end of the pedal to get the angles right, and... Here's the parts separate:
Another pic showing my original pedal next to my modified version. Here's the parts put together. A little blue threadlock on the bolt and it looks like this:
So out in the engine compartment for the termination end at the throttle body, I made a bracket that mounts where my AAR used to attach. I have switched over to a different throttle body and the AAR is no longer needed so those holes were re-purposed for my cable bracket:
And here's another pic of the bracket up by the throttle body. Note that doing it this way also allows me to adjust the throttle cable play extremely easy using the original Civic adjustment nuts:
I'll talk about the cable itself in a little bit.