Really embarrassed to ask his question.....

Fuel pump.
Is the top the inlet from tank, and the bottom the outlet to the carbs?
Just fitting the last little bits to my rebuild.
So, as a treat, I'll give you a photo

 

There should be a inlet and outlet arrow in the pump

 

Really? Don't remember seeing one.
Will have to check again
Cheers

 

Yes upper from tank, lower to carbs.

 

Super!

So, not the more embarrassing bit. I did it the wrong way round!
Good job I checked!