READY TO GO RACE HEAD
These heads use Genuine Honda cores (these flow better, are less porous, and stronger than Aftermarket heads). Heads are ported, bead blasted, flowed, & milled. Stainless Valves. Heads can be fitted with either single or dual springs. Single Springs recommended for 306 and smaller cams. Dual for 307 and larger cams.
GX390 Heads have choice of 36mm Intake or 40mm intakes
We offer heads in two port sizes
Our "Large Port, High RPM" head (this one) use large port castings to increase hign rpm power at some loss of low end torque and reduced throttle response. They can provide increased cooling for endurance applications.
We also offer a "Small Port, Torquer" that uses small port castings to increase velocity maximize low end power at some loss of high end rpm. IT IS BEST CHOICE FOR MOST APPLICATIONS
390 heads will fit 340s.
Includes
Ported, Polished, & Bead Blasted
Stainless Intake & Exhaust Valves
Aluminum or Titanium Retainers
HD single or dual springs