accelerator cable 71

My nova is a 71 with a edelbrock 4bbl carb. The accelerator cable started to fray so I decided to replace it. I bought a kit from a performance parts store in my area. The problem is that the rubber piece that allows the cable to pass through the firewall won't be used again. I somehow dropped the screw that holds it in place (stupid i know, ill find it tommorrow cause I had to go to school). Anyway, the new kit uses a screw and a nut and only uses the big hole that origionally had the cable pass through. It consists of a nut that is hollow and then is bolted on the back by a nut and washer. My question is: can I just use this new universal throttle cable and cut it to size and just leave the other hole empty?(the hole that is threaded and held the origional rubber piece, or should I go to the bone yard and look for another screw/rubber piece if I'm unable to find the screw. Should this universal kit work if i trim / cut to size and use only the bigger original hole?

Just a funny for ya guys too: After I took out the old cable, I found that the owner before me used a fishing weight to use up slack on the cable...:screwy: