Inlet elbow and hose size

I've replaced the fuel inlet with the CV brass unit which will take a 5/16 hose. My hi-flow petcock is 3/8. All the petcocks I can find are either 1/4 or 3/8. All the elbows are 1/4 or 5/16. I "might" be able to fit a 5/16 hose on the 3/8 petcoack but it will be sure to split after a while. Right now I've got a 3/8 hose on and the clamp (after stripping a couple to get tight enough) isn't leaking but it's cutting into the hose enough that I know it will be a point of failure. What gives here? Why the disparity in sizes? And what do I do to correct it? Thanks.

Already spent big dollars on a Pingle hi-flow with a 3/8 outlet so that ain't happening. What I don't understand is that there are so many 3/8 petcocks and no elbows. I think it's time to get out the drill and the tap set.

Lemme see - 3 maybe 4 years. Don't think that's an option. So where can I find a 3/8 inlet? I'm assuming I'll have make one or use a standard brass fitting.

If cost is a concern, Golan makes a nice fuel valve as well. Way less than a Pingle. Just a suggestion.

Cost is always a concern! I'm retired on a fixed income. I'm not going to buy another petcock after spending well North of $100 for what is supposed to be one of the best.

Another option is you could find an inline hose adapter with 3/8" on one side and a 5/16' on the other and connect it that way for now just to buy you some time until you can fix the issue properly. Use appropriate size corbin clams on each side, done.. I wouldn't leave it that way for long as it will screw up flow but it will get you back in the wind until you can fix it properly...

Thanks for all the input. For right now I'm just going with a 5/16 rubber hose forced onto the petcock. Not a proper solution but it'll work.