door and jmark got it right, i was told to relieve pressure in the block,
that caused leaks and other gasket problems and yes the hp comes
from pressure free movement, i.e. crank, rods, some have gained
hp and some that have already have a good evac system did
not gain hp but i bet if the engine could talk it would be relieved
i have never ran one but w/a first bbc 496, EFI i am going to
try a vacum system from aerospace compnents, good luck bud :wink: