Is there a certian manifold to run twin webbers on 1600 to clear standard brake booster or not? Cheers

I think some are better than others but none will clear. Lowering the booster bracket is one way to get around it

Ah ok so there is no specific manifold that will clear the booster in standard position

Hi mk1escort,
 
A bit late, I know but I looked at having a custom manifold made up to convert my Kent into EFI, but it was going to be too costly as a result. One part of this process was changing the brake system over to a hydraulic one and doing away with the booster altogether. I wanted this option anyway to make the engine bay look a bit less crowded, but instead just went with the GT manifold and single 32/36 DGAV.
 
Anyway, the reason I mention this is because I was looking at a bunch of stuff on Burton Power and was looking trough the Kent Motor Fitment Parts List which had a bunch of stuff that may suit your needs. I'm not sure what the clearance is but something like this might fit... They have a bunch of other stuff there that might be of interest.
 
It's normally quite expensive to get parts sent over, but I think most members here will arrange to share postage costs, so if you do end up getting something give a shout out to your fellow car enthusiasts.