Aussiespeed® Holden Blue and Black motor 4 barrel performance manifold is not for a mild street engine, the manifold is for engines with modified cylinder heads and camshafts. The widest measurement from the cylinder head face to the widest point on the plenum side is 225mm.
Many engines will respond to the use of a spacer between the manifold plenum and carburetor. Due to height restrictions and keeping the carburetor and air cleaner on most model Holdens under the bonnet the plenum height is lower than optimum for some engines.
Aussiespeed® Holden 6 cylinder performance manifold is designed to be used on Holden Blue and Black motor 12 port designed cast iron and Yella Terra 12 port aluminium cylinder heads. The manifold has one x 1/4 npt vacuum take off on the rear of the manifold for brake vacuum and auto transmission fitting.
The carburettor can be mounted in the normal north south configuration and is also drilled for east west carb mounting how ever some additional grinding may be required when mounting carburettors sideways. AS0574 is an adapter that can be purchased separately and fitted to mount a 2 Holley 350 or 500 2 barrel carbs to the AS0002 in either front to back or in the sideways position