Stop messing with jets and float levels. The Holley Sniper EFI system bolts on where your carburetor used to be and tunes itself in 50 miles.
Cold starts every time. No flooding. No vapor lock. Your Camaro will start like a modern car—because it has modern fuel injection.
The Sniper kit includes a 4150-style throttle body (looks like a carb from 10 feet away), touchscreen controller, fuel pressure sensor, oxygen sensor, and full wiring harness.
Base kit: [Holley Sniper EFI 4150 (550-510)](https://www.amazon.com/dp/B00KZMO7ZU?tag=rusttoroad-20)
Disconnect fuel line, throttle cable, vacuum advance, and PCV. Unbolt the carb (four nuts on the intake manifold). Lift it off. You're halfway done.
Clean the intake manifold surface. Drop the Sniper on using the supplied gasket. Torque the nuts to 10 ft-lbs in a cross pattern. Don't overtighten—the throttle body is cast aluminum.
EFI requires 58-60 PSI fuel pressure. Your mechanical pump maxes out at 6 PSI. You need an in-tank electric pump or a high-pressure inline pump.
In-tank option (best): [Holley Retrofit Fuel Module for 1967-1969 Camaro](https://www.amazon.com/dp/B01LZDQKUO?tag=rusttoroad-20)
Inline option (easier install): [Holley 255 LPH Inline Fuel Pump Kit](https://www.amazon.com/dp/B001UE7270?tag=rusttoroad-20)
EFI needs a return line to send excess fuel back to the tank. If your tank doesn't have a return fitting, add a return-style regulator at the tank.
Return regulator: [Aeromotive Bypass Fuel Pressure Regulator](https://www.amazon.com/dp/B000CNH9WE?tag=rusttoroad-20)
The Sniper harness has six wires: switched 12V power, ground, tach signal, fuel pump relay, and two for the oxygen sensor. Color-coded and labeled. Takes 30 minutes.
Oxygen sensor bung (if not installed): [Weld-In O2 Sensor Bung Kit](https://www.amazon.com/dp/B000CZDV7Q?tag=rusttoroad-20)
Turn the key to ON (don't start). The touchscreen walks you through setup: engine displacement, cam type, target idle RPM. The system handles the rest.
Crank the engine. It'll fire in 3-5 seconds once fuel pressure builds. Let it idle for 5 minutes while the system learns. Drive it for 50 miles—the Sniper adjusts fuel maps in real-time based on the oxygen sensor.
- Sniper EFI 4150 kit: ~$1,100 - In-tank fuel module: ~$400 - Return regulator (if needed): ~$90 - O2 sensor bung: ~$20 - Wiring supplies: ~$30
Total: $1,640 in parts. Worth it for the cold start alone.
Engine cranks but won't start: Check fuel pressure at the Sniper inlet with a gauge. Should read 58 PSI key-on. If low, your pump isn't working or the regulator is set wrong.
Runs rich (black smoke): Oxygen sensor wiring might be reversed. Check voltage at the sensor connector—should fluctuate between 0.1V and 0.9V when running.
This is the single best upgrade you can make to a carbureted Camaro. Better throttle response, better fuel economy, and zero tuning required. Your passenger won't know it's EFI until they see the touchscreen.
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