Having replaced engine I was hoping to use my old fuel lines and rails, but looks like they are leaking so that's that!

I currently have parallel fuel lines with an fittings, but I have also had them come loose in the past, which doesn't end well.

So I wanted to go with push fit lines( on proper barbed fittings with fuel hose clamps) as I trust that, but been advised by supplier against it.

It is in my rally car, which sees Tarmac and dirt, but standard fuel pressure - so any views on what people use in competition cars?

I know an fittings look pretty- that is of no interest to me- I can't see if they are loose easily