These heads produced by AAPistons are knockoffs of the 039 101 371A heads that came on pre-smog 2.0 914/4’s. They are often referred to as
Category: 914/4 Type 4
VW Type 4 Crankcase Breathing System Testing & Analysis
This article explores and unravels the mysteries surrounding the sometimes controversial issue of venting Type 4 cranckases, for street and track cars.
