Gain a couple hundred rpm, reduce lap times and nobody will ever know your have a modified intake manifold
Acid Ported: For applications where your intake must retain a stock look, even if the manifold is pulled off the motor. Our acid porting procedure removes over 2 pounds of material from the internal parts of a Small Block Chevy cast iron intake manifold. Other manifolds, like cast iron Big Block Chevy intakes, have over 4 pounds removed. Nothing on the outside of the manifold is altered. And, the plenum area and port openings retain their stock look and dimensions! Typical performance gain is 6 to 11 horsepower is gained over a stock intake manifold. .

During the acid procedure approximately 2 pounds of material is removed from the manifold. The manifold retains a totally stock external appearance.
If you are not allowed to port the intake, our acid porting procedure will do an awesome number on stock cast iron intakes. On an engine running 6,500 to 7,000 rpm we’ve seen a couple hundred more rpm. And the best thing is the acid modifications will be just about impossible to tell, even if the manifold is pulled off the engine.

When compared side-by-side to a stock intake, the acid modifications are virtually undetectable. Most engine builders couldn’t tell our acid intakes from a stock manifold!
So, you get the best of both worlds: A faster race car and no one will ever know.
Part#
Description
201XXXX
Acid Ported Small Block Chevy 2 barrel intake manifold
401XXXX
Acid Ported Small Block Chevy Q-Jet 4 barrel intake manifold
406XXXX
Acid Ported Small Block Chevy Holley 4 barrel intake manifold
In the original form, the Chevy cast iron intakes were designed to run from idle to 3,000 rpm. However, on a race engine, the engine never sees anything less than 3,500 rpm on the track. This is the reason the stock intakes are so restrictive for a race application. As the dyno charts show, the addition of a ported cast iron Brzezinski intake will add horsepower to your engine from 3,500 to 7,000 rpm. If you are interested in performance below 3,500 rpm, such as for a tow vehicle, keep the intake stock. If winning races is your goal, get one of our modified intake manifolds.
