Recently purchased a 1983 Cole 21 ft V-drive day cruiser with a 468 BBC PRM twin turbo set-up. This is a draw thru system with a simple intercooler attached to a single plane manifold.
There are two intake control valves located between the outlet of the turbo and the inlet of the intercooler.
Does anyone know what they are for? They are normally open and close with manifold vacuum.