Ready-to-Go Race Head for GX390 with Genuine Honda Core

Ready-to-Go Race Head for GX390 with Genuine Honda Core
This head uses a Genuine Honda core for better flow, less porosity, and higher strength than aftermarket heads. Head may be fitted with either single or dual springs. Single springs are recommended for 306 and smaller cams; duals are recommended for 307 and larger.
GX390 heads have the options of 36mm, 38mm, or 40mm intakes.
*GX390 heads will fit GX340s.

We offer heads in two port sizes:

"Small Port, Torquer" uses small port castings to increase velocity and maximize low-end power at some loss of high-end RPM. These are the best choice for most applications.
"Large Port, High RPM" uses large port castings to increase high-end RPM power at some loss of low-end torque and reduced throttle response. They may provide increased cooling for endurance applications.

Product Includes:

Ported and bead blasted head, milled to specs
Stainless intake and exhaust valves
Aluminum or titanium retainers
Split keepers
HD single or dual springs
Valve spring shims
3-Angle valve job

*Note: Heads are typically built to order. Please allow approximately 1-3 days before shipping.