Dude, I will be buildimg one of these after my blown car is completed. The easyest way to force feed an "A" is a drawthrough turbo with an SU or stromberg type sidedraft. If you monkey with the needle and get the mixture right for the engine while it is still NA, it should provide the right mixture whilst drawing through. If big boost starts to cause detonation, A water injection set up can be built cheap as chips.
That is the cheapest way to make it haul ass. if youcan do the work yourself . it should be doable for less than the price of twin sidedraft. Leave Injection for poeple with too much money.