Mk1 20v- Do i need to change the old fuel pipes?

Hi .

 I am at the stage of sorting the fueling out on my mk1 project.  I have all the pumps etc.  My car was a 1.6 carb before i swapped the 20v.  I am now thinking the original hard pipes running throught the car are too small.  Not sure exactly what size they are but 8mm I.D hose is far too big to be clampd onto.  

Do i need to run new pipe/hose?  

If so will copper pipe be sufficiant?

Cheers.