Summit 11,000 RPM 4" tach $50. 8 cylinder only. Built-in shift light & rev-limiter.
AutoMeter rev-limiter $50. 4/6/8 cylinder. Up to 11,275 RPM in 250 RPM increments. Adjustable delay 0.1-1.0 second. Has button for half-speed test. Output has both NC & NO contacts available.
Many years old but I believe these are fully functional- will refund money if not.
