As we've mentioned before, the team here at Nuts & Bolts are true fans of high revving, naturally aspirated motors. There's nothing quite like hearing a car scream to RPM gods (we love old low displacement V10/V12 F1 engines).
Here is Skunk2's Alpha Series valve spring and retainer kit. This kit became well known throughout the Honda world with their B-series VTEC engines. Each valve spring is manufactured exclusively from super-clean, chrome-silicone wire milled in Japan. By using inner and outer springs mated together through a slight interference fit and with differing frequencies, Alpha Series valve springs are able to prevent valve float and maintain valvetrain stability at engine speeds in excess of 10,000 rpm!!!
Skunk2’s industry-leading Alpha titanium retainers are designed to significantly reduce valvetrain mass, resulting in more horsepower and improved valvetrain stability. Alpha titanium retainers feature radius-cut edges for additional rocker arm clearance and reduced weight, strategically positioned lightening grooves, and reduced overall heights for better valve seal clearance and even further weight reduction.
If you're building your dream NA FA20, then we highly recommend Skunk2's kit!