Its vague enough to be useless!

Well, when torquing down the injectors, I must ahve pulled one of the return lines off.

A few minutes later I see that that hole , #6, is full of fuel.

So I reckon that I had the return/feed lines crossed as the retun lines filled with fuel. Tonight I'll put the car on stands and take a gander underneath.

Suppose it could have filled through the return line ( the fuel tank is full btw).

Is there any DEFINITIVE way to know which one is feed and which is return?

Other than being carful to frickin LABEL THEM when I disassembled it in great haste?