There is no valve clearences they have hydraulic cam followers.

If you've got a 1.4 on it still then change this thats not doing you any favours, i'd love to know how exactly the fuel pump is connected to the tank if it is like u say the original 1.4 tank, should be highly amusing

Theres no way the fuel pump is going to be able to suck enough fuel up from the 1.4 outlet, and would probably also explain why the pump is so noisy......