M120 Motor Development

We offer an entire product line of M120 performance parts. From performance and swap parts, to full Turn-Key engine packages 

We are currently working on uploading the full catalog to the site. 

CNC Ported M120 Heads (Mild to Full Race Spec Built Heads)
Turn-Key Engine Packages (Street to Full Race)
Full ITB Intake Setup
Full Standalone Haltech EMS Harness
CD009 Adapter with Clutch and Flywheel
Titanium EGR Block-Off Plates
Race Alternator Bracket
Full Billet Dry Sump Kit
Billet AN Water Block Plates

Please see the video below outlining our engine packages and for more info on what we offer.

The Challenge

Every successful product is the fruit of hard work, and our development of a 20yr old platform is no exception. We have developed the m120 engine to a level that has never been seen before. It all started with the decision to M120 swap our shop vehicle "PistachioFD". After seeing that was practically zero aftermarket support for these engines we decided to develop things ourselves. This allowed us to design and make our own catalog of parts, and in typical Gooichi fashion it snowballed. We now have a full catalog of swap parts to make transplanting this iconic motor into any platform easier then ever. 

The motor development is on another level as well! We have drastically redesigned the rotating assembly and heads. Countless hours have been put into R&D and testing, taking the M120  from an already great motor to an ultra high performance engine. We have given things a fresh look, and thought outside the box, and I think you will be happy with the outcome.  

Heads

 We offer a full 5- Axis CNC Ported head package, along with custom valvetrain, and billet camshafts suited to your application.  This top end setup is something that hasn't been offered before on this level. Without spilling the beans, these suckers FLOW. The heads have been flow tested with our ITB setup, allowing us to spec out a perfect valvetrain setup to hit 9000rpm reliably. Reworking the valvetrain design has allowed us to make drastic improvements in the performance of an already great platform. 

Rotating  Assembly 

Reworking the rotating assembly has given us a Rod/Stroke ratio higher then anything seen in an m120. This allows us to wind these motors up, allows for less friction loss on the cylinder walls, and greatly improve performance. We offer Pistons in 6 different dome heights for Low compression boost applications up to a 12.6:1 NA screamer. Our custom rods are available in 300m and Titanium, and can support upwards of 1200HP in their base trim. Lightning the rotating assembly keeps them very rev happy.

Dry Sump System


We have developed a full 5-Stage Dry Sump system, including a Full Billet Dry Sump pan! If you dont know the benefits to going dry sump let me tell you. Freeing up air friction and viscosity allows the engine to free up lost HP. Stable oil pressure and temperature. Larger oil volume. Also our Billet Dry Sump Pan gives you an extra 6" of ground clearance!


Engine Packages


From a mild street motor to full race we have recipes for you. NA or Boost we can make it happen.  We offer 3 stages of engine packages depending on your needs, so please contact us to spec out your perfect engine package!

M120 Product Page


Professional Support for Your Custom Project


Got a challenging project and need expert guidance? The Gooichi team offers personalized, one-on-one support to help you achieve your project goals with the care and expertise you deserve.


We’ve not only developed innovative products for the M120/M104 platform but have also successfully completed numerous conversions using a variety of transmission combinations. Whether you’re aiming for specific power targets or need recommendations tailored to your needs, we’re here to help bring your vision to life.


Before Your Call:
To ensure we can provide the best assistance, please have the following information ready:


  • Vehicle model
  • Power goals
  • Vehicle’s intended purpose (Street, Race)


Important:
A minimum charge of one hour applies to all consultations, which must be booked and paid for in advance through our website.

Let us help you take your project to the next level!

Book Professional Support

GMS M120 Price Catalog


Here is our M120 product price sheet and catalog, featuring our latest offerings for the M120 platform. This catalog will be updated regularly as we continue to develop and expand our product line. If you're looking to build a specific package tailored to your project goals, please don't hesitate to contact us — we'd be happy to help you formulate the perfect setup. Feel free to reach out with any questions or for more detailed information!