replaced cluster, still no gas gauge. please help!

I have a 96 LS with a GSR B18 C V-TECH swap that i recently bought. everything up til now has been repaired (mostly electrical issues). the only problem left is that my speedometer and gas gauge don't work. (new cluster, I'm in need of a speed sensor.) but i'm not sure about the fuel gauge. the fuel pump is working properly but that's about as far as i know. If anyone could give me some advice as to what i can do to fix the problem i would greatly appreciate it.