REDUCER FOR FUEL LINE TO CARB

The old guy and his son who put a 318 in my 67 Barracuda, have a fuel line coming off the carburator of what looks like a 8 inch long rod.
The problem is the adapter on the end is probably 1/2 inch diameter, and they have run this one 1/2 inch rubber hose to the 5/16 inch nipple off of the fuel filter.
They used 2 hose clamps near each other to close down the 1/2 inch line enough on to the 5/8 inch fuel filter nipple.

I notice thai as I was replacing the fuel filter,. and had a devil of a time tightening the hose clamps down enough to not get a fuel leak.
It looks to me like what is needed is a reducer hose from 1/2 to 5/16.
I can't seem to find a rubber one that size; but found a Silicone reducer.
My question is ......Is Silicone OK for the fuel line?? Most of what I see on the WEb says "No".

And I admit that I hadn't removed the 1/2 inch hose off of the carb rod yet.
It was pretty resistant to removal, even with the clamp loose, and I didn't want to dig a bigger hole for myself.
It could be that they clamped the rubber hose over what could be a fiting at the end of that rod, just being lazy. Wouldn't suprise me from the other stuff I have discovered.
And, I just might need a fitting with a hose adapter on the end.