We are getting a new gas range and we didn't know if the current gas valve should be replaced or not since it is an old valve. It looks like it is outdated and needs to be replaced. Should we get this replaced?

 

Yes, I would recommend you change the valve to something like this: (not in stock but available)

Eastman 1/2 in. x 1/2 in. Angle Flare Brass IPS Gas Ball Valve-60034 - The Home Depot

It's safer and should allow you to install the range close to the rear wall. You might also need a shorter pipe coming up through the floor.
Most modern ranges only give you about 6" or so from the floor to fit the valve and flex line in the cavity behind the range.

 

Definitely get it replaced.
If you don't change it yourself.... you'll need to get a plumber.
The appliance delivery company cannot change a valve.
If you replace that valve you will be required to turn the gas off at the meter.

 

Its going to be tight trying to get that off and the new one on. Is there enough room between the drywall and that pipe to spin the valve

 

The basement has a finished ceiling. To shorten the pipe, would that mean opening up the ceiling to make this happen?

The pipe is far enough away from the wall to replace the valve. If I were to replace the valve, not shorten the pipe, would the steps be: shut off the gas at the meter, unscrew old valve and replace with new valve, and then check for leaks?

Thanks for the input on this!

 

I don't recommend you work on your own gas fittings. If you do, you are correct. Shut off gas at meter and remove valve. Use two wrenches (pipe wrench and a crescent wrench) and ensure the pipe going down does not turn or be disturbed in any way.
Once the valve is removed clean the male pipe threads with a wire brush or wire wheel on a drill.

Apply pipe dope to the male pipe threads only, not the internal threads of the valve and tighten it.
Do not use dope on any of the flare/flex line connections, just use 2 crescent wrenches to tighten the flex line firmly, one holding the valve and the other turning the flare nut.

You MUST be familiar with lighting pilots to do this. If there's any doubt call the gas company and they will usually light them for you at no charge.
Turn off the main gas line and any lines/valves going to dryers or furnaces and water heater.
Usually the only pilot you need to relight is the water heater, but make sure you know what you are doing.
Make sure the furnace has electronic ignition and make sure it functions properly after doing the repairs. Turn it up to a high setting and check flame is lit.

RectorSeal 1.75 oz. #5 Pipe Thread Sealant-25790 - The Home Depot