Bigger is better in this case.
Make sure to use the yellow teflon tape or gas approved pipe dope and check for leaks!
There's also suppost to be a gas shut off there where it comes out of the wall before the hose.

 

Thanks Joe. I do have a shut off right there and have some Locktite pipe sealant that is approved for gas.

 

If the fitting on your gas line is 3/8" then I don't see how using a 1/2" flex hose will 'help' per se, but it certainly won't hurt. Now if there's a 1/2" to 3/8" reducer on your gas line I would remove that and hook up your flex line directly.

 

Both ends (range end and hard gas line end) had 3/4" to 3/8" reducers. I am putting on 3/4" to 1/2" reducers to make the new flex line work.

 

Gotcha, that makes sense.

 

Soapy water to check for leaks, right?

 

FYI: don't use dope on the flare fittings for the flex.

 

A little pipe dope on the flare fittings and threads will not be a problem

 

Do NOT put pipe dope on flare or compression fittings no matter where you live. It has no value on a connection that's correct and only makes it aggravating for the next plumber. If you must put something on something put a couple drops of lubricating oil on the threads.