AA Bare 2.0 Porsche 914/912E Head Casting. Build the performance Head of your needs. It Comes bare with out Seats or Guides. Giving you the the ability to build any possible combo Stock or Street head you want. The AA 2.0L casting comes with the STD Porsche 2.0L combustion chamber. The STD Porsche 2.0L Spark Plug angle. Also equipped with a breather pipe and all the studs