Stage I HV Twin-Cam

     The Atwood Performance stage I package offers the best bang for the buck in the industry. The stage I package includes:

• Full porting of both intake and exhaust runners.
• Polishing of both intake and exhaust runners to each' ideal finish.
• New manganese bronze guides.
• New viton seals.
• Competition multi angle valve job.
• Full flow test from .100"-.600" lift range upon completion.

     HV refers to high velocity. By retaining the stock valve sizes, maximum port velocities are retained, and even improved upon after porting.

     The Atwood Performance stage I port work is not your average stage I port job. Average flow is normally 250 cfm on intake and 200cfm on exhaust. No where else on the market will you find this kind of performance at the Atwood Performance price. One of the reasons that Atwood performance cylinder heads flow so well, is the stock HD guides are removed during the porting process. This makes room for the carbide cutters to really get in and around the roof of the port for large improvements in air flow that would otherwise not be possible if left in place. Then, when finished, high quality, high flowing, manganese bronze guides are installed for the highest airflow and durability possible. 

     This is what a stock Harley Davidson exhaust port looks like.

     This is the Atwood Performance finished exhaust port.

     This is a stock intake port with the guide still in place.

    This is the Atwood Performance intake port with the new manganese bronze guide installed.

Prices start at 399.00. This includes all the services listed above. Services are to be performed on your heads.

Options include:

• Measuring of combustion chambers in CC's -25.00
• Milling of the heads -50.00
• Installation of compression release valves -100.00
• New AV&V valves of stock size -80.00
• New .560 or .600 AV&V springs -80.00
• Titanium retainers -50.00