Slick 60's

Some of you may have experienced the same problem as I have with throttle not returning to idle. This of course could be a result of the throttle cable, which is not very good in my opinion, but trying to et it to work right by changing spring tension, and it is not working out all that well. First let me state the throttle does not want to come off the idle position, and takes to much pressure which makes the old gal harder to drive. If I stretch the spring then it does not want to go back to idle. Cable seem to be in fairly goo condition although used and not new. I also have another problem and that is the carb does not want to idle down all the way. I'm wondering if the wrong carb has ben installed sometime in the past. I have to put to much pressure on the foot pedal to get it off idle. Annoying at the least as the engine will be turning to many rpm for easy driving. I am also am working on my grandsons truck which I have installed a 351w in. Using the later mounts puts the engine and carb further back in the engine bay, which leaves the a tight circle for the new carb cable. I don't like the setup and think it will cause problems in the future. I am using a modified 352 bracket and original replacement style cable. Frankly, I've never liked the original cable setup but personally know of nothing that is an easy replacement. I have 351w cable brackets for the intake, but this uses a different cable and again it would be twisted around in a pretzel fashion. Any solutions out there that don't bankrupt the bank. As is, I have 35 plus shipping in the NORS cable I used.

I personally like the throttle "rod" better than I do cables. You can get the "feel" better. Sorry. no help on yours. One thing I might note, on my truck the idle would never return back to the same place, found out it was the advance in the distributor sticking...

I have had this problem also, but totally different engine and cable setup. Just for some trouble shooting, had you tried disconnecting the throttle cable and checking the off idle from there? That way you can determine if its the return springs in the actual carburettor itself, or the pedal/cable setup.
I have sprayed considerable carburettor cleaner to all the linkages and springs, I also found the pivot pin on the actual gas pedal setup itself was binding, however mine had a RHD style pedal setup and I don't know if yours is a floor pedal or a suspended pedal. Some WD40 would fix that problem. In the end I changed the carb return spring and also added a pedal return spring to my gas pedal.

You can also get a sticky throttle if you have gunk built up around the throttle plates. This will cause stickiness at idle. Clean with carb cleaner. Never had this problem with a slick, but there is also less buildup with the new gas formulations.