The parking brake on my 74 is not holding for .... The venting is right on and the brake handle ratchets up properly. I searched but couldn't find, is there a way to tighten the cable or???

Jack up the car and look under where the engine bay is, on the driver's side base of the firewall is where the parking brake cables exit, one goes straight back to the driver's side wheel, and the other runs along the firewall to the passenger wheel.



The spot where it exits the tubes, there's a rubber piece that protects the threads for adjusting the cables. Slide the rubber off (unless it's completely gone by now!) and you should see a pair of jam nuts. Un-lock the nuts and thread them further in to remove the excess slack.



That being said, other possible causes can be at play here and should be inspected while you're troubleshooting.
Brake caliper might need a rebuild.
The inner sheath on the parking brake cables might be binding and preventing the cable from being pulled through smoothly.
I'd also pop the driver's seat out, and inspect the brake cable equalizer under the carpet and protective cover, make sure all the cables are operating smoothly.

Each parking brake cable is adjusted at it's tube on the lower part of the firewall. There's two nuts on each cable that you've got to loosen to make the adjustment, 17mm IIRC. The workshop manuals say to adjust the cable until the stop at the caliper just comes off the stop. You also want to make sure you don't lose any venting clearance on the inner piston