Edelbrock 5/16 inlet options

I searched the forum and found this question asked a few times with no answers. I'll explain the situation and be more specific. Hopefully someone has found an easy solution for this.

My 360 LA has an Edelbrock 600cfm performer on it. My car (71 dart) has 5/16 fuel line, hard line, in great shape. I do not want to change over to 3/8. From the pump to the carb is mostly hard line, but I will run a small amount of rubber line so I can use a cheap and available fuel filter.

The stock fitting on an Eddy is 3/8 as seen here (on the top left)


I want to replace that inlet with something like this:


Yes, I want a barbed/press on fitting like that, so I can easily put a fuel filter between the hard line coming from the pump. So hard line from pump most of the way > short piece of rubber line > filter > short piece of rubber line > above fitting to carb. Pretty standard. The problem is everywhere I turn the barbed/press-on fittings are 3/8, NOT 5/16. Summit even sells their own kit as do other companies, as seen here (also 3/8)
http://www.summitracing.com/parts/sum-g1532/overview/

I'm guessing none are sold for 5/16 fittings. But take a look at this, here's the same kit but it shows the pieces disassembled:

Notice the barbed/press on fitting. What kind of fitting is that exactly? If I knew that i'm sure I could find the same thing but 5/16, and use it.

Comparing those threads to other pictures on here, I believe it is a -6 AN fitting? But it has a tapered end...
http://www.edelbrock.com/automotive/mc/carburetors/access-fuel.shtml

Thanks guys.