The Revolution Performance 1.9 Evo Big Twin heads are a product of countless hours of physical research and development to produce not only big torque but reliable, broad power delivery. Ports are developed using state of the art Superflow 600 flowbench technology and port flow analysis software as well as real world know how to bring a perfect union of volume and velocity. What does this mean for the customer? BIG torque! Let’s face it, the real world is not full of dyno shootouts where mostly unusable high end horsepower is key.
All heads are upgraded to one piece severe duty stainless steel 1.900" intake and 1.615" exhaust valves. Valve guides are replaced with bronze manganese for the utmost in durability and heat dissipation along with Viton rubber valve guide seals. Valve springs are replaced with superior quality chromium silicon units with lightweight Titanium retainers and 10 degree valve locks.
You can either send us your heads to be ported or we can do a core exchange.

PLEASE NOTE: Core heads being returned for credit need to be returned within 30 days for full credit. See our Return Policy for more details.