Fuel Injection Hose - Diameter & Pressure Rating?

I thought replacing the two bulk rubber fuel injection hose pieces on my car would be easy. It turns out finding Fuel Injection hose, let alone hose in the correct diameter has proven difficult. for my 92 740 Turbo

I'm asking the board to confirm diameters for me, and perhaps direct me to a sufficient source. I usually buy Gates bulk hose, and I thought it was a readily available commodity in most any auto parts store.

Fuel main pump feed...1/2"
Fuel rail return...5/16"

The return needs to be high pressure, but what about the main pump feed? I have no idea the pre-pump pressure capability.

12 mm for main fuel hose
7.9 mm for return

Bel metric has what you need.

It's too expensive to buy Gates hose in bulk. That's usually what I would do. Instead I just buy enough for what I need and 2 extras.

7.9mm for return?

They show 7.5 or 8mm


Ordered the fancy braided stuff. went with 8mm for return. Thanks

I was giving the exact diameter but 8 mm or 5/16 would be the hose that's available on bel metric. You could also of bought direct from Volvo.