Maybe, but it might create a likely fail point and beer foam might come rushing out, all over the place, when you are not home.
The retailer has a solution, I'm sure. I've always used 1/4 inch gas line. You could always swap the 5/16 inch fitting on the bottom of the regulators for 1/4 inch, and use 1/4 inch line, but that's a big pain, and I think the retailer will have something better to suggest.