was it a new sending unit?
I gotcha Wild Bill....here's two answers and I'll break it down...sorry if some of this is obvious, but here's the details.
1. You should get your steering column tight. It's your steering. The steering column is held in "mainly" by a black metal plate underneath it. There's two nuts with funky star washers that you can see under the column/dash & right up front. The two studs go through some "white, split, rectangular-looking" plastic spacer things & the funky star washer & nut goes over those two studs.
On that same black metal plate, further down towards the floor, sort of above your left ankle is a bolt (not a nut) that goes through the same type of "white, split, rectangular-looking" plastic spacer thing as the front two nuts/studs. Why the back one is a bolt and the front two are nuts/studs???? Who knows. Anyway, those 2 nuts/studs & 1 bolt hold that whole black metal plate up against the dash.
Looking at that same black metal plate, closer towards the steering wheel, along the bottom, there are 4 bolts (2 on each side) attaching the black metal plate to the steering column itself. Usually at least one of them has a short black ground wire going between it & one of the stud/nuts I've already mentioned...fyi. These are probably the first bolts you'll notice holding the steering column in.
Lastly, down past your feet & attached to the metal floorboard/firewall of the car itself is the lower column bracket. There's a big black metal "floor plate" down there bolted to the floor/firewall with 4 bolts. Where the steering column goes through that big black metal "floor plate", there's a "ring" around it and two bolts hold that "ring" (and the column itself) to the metal "floor plate"
This is everything that holds the steering column itself in the car....so please make sure this is all 100%. Sorry if I'm boring.
2. Sending Unit & Gage: The "sending unit" is really a 1-part-does-3-things piece that's inside your gas tank front/center/on top/just above the rear end u-joint area. It is a)metal tube "straw" where the fuel pump sucks gasoline out of the tank b)a toilet bowl float (thin metal arm with a float on the end, just like inside your toilet) and c) a variable resistor (? I think? rheostat?) ....anyway, and electrical thingy that is connected to the "toilet bowl float" that basically tells how much gas you have in the tank by seeing how high up the "float" is and turning that into a signal that it sends to the gage.
Back by this sending unit (under car, center, top of gas tank, front part) you'll see a fuel line hose (or two) connected and one lonely wire with a "L" shaped push-on & pull-off type connector. That's the wire that sends the signal to the gage.
Disconnect that wire (just pull it off) & run a piece of wire from that "L" connector to either the negative side of the battery or to a good ground (sand a small patch of thick metal under the car somewhere down to bare, shiny metal)...either way, a good "-" ground.
Put the key in the ignition & turn it to "run" (no need to crank it by going all the way to "start", just "run"). If your gage is good (& the wire leading to it) the gas gage should go all the way to "full" and stay there.