You will need to remove the modualtor & block off the govenor circuit. There is also mods to do in the valve body. leave it to the pros. Because you now have a minifold tube per cylinder you can only take vacume from 1 cylinder so thats probably not enough. if you can some how get vacume from all cylinders it might make a differance. Thats the only logical explanation i can think of. Something i did on a turbo 400 in a ferari once was put a restrictor in the vacume hose because it was getting too much vacume. There is heaps of other things it could be if you want any help PM me.