Fuel gauge Fail!!!

[Vicious Beaner!]

My gas gauge on my cluster just happened to go out about a week ago and just started staying towards the "E" or quart mark. and not go above that! so i just opened the cluster and tried putting in another gas gauge mechanism from another cluster and its off same deal!
Now i want to see if its the actual gauge before i have to open up the fuel tank and check the floater on the fuel pump. which i highly doubt because its a newish walbro. Also the gas gauge i replaced on the cluster was givin to me from a friend and i think he might of touched the needle on it and might of threw it off! So my question is anyone have an after market fuel gauge thats acurate. ? Any input would be greatly apprciated!
Im just tired of guessing how much gas i have in my car and just run out of gas like before .

thanks!