Carburetors are romantic until they flood your garage with gas fumes. The Holley Sniper is the easiest EFI swap you can do—no laptop tuning required.
Modern fuel injection without the complexity. Self-tuning system learns your engine in 50 miles. Cold starts, hot starts, altitude changes—it handles all of it.
The Sniper kit includes the throttle body (looks like a carb), fuel pressure regulator, wiring harness, oxygen sensor, and a 3.5" touchscreen controller.
Base kit: [Holley Sniper EFI 2300 (550-516)](https://www.amazon.com/dp/B001234580?tag=rusttoroad-20)
Disconnect the fuel line, throttle linkage, and vacuum lines. Unbolt the carb from the intake manifold (four nuts). Lift it off. That's it—you're done with carburetors forever.
Drop the Sniper on the intake manifold using the supplied gasket. It uses the same bolt pattern as your old carb. Torque the nuts to 10 ft-lbs (don't overtighten—you'll crack the throttle body).
EFI needs 58 PSI fuel pressure. Your mechanical pump can't do that. You need an in-tank electric pump or an inline pump near the tank.
Recommended pump: [Holley Retrofit In-Tank Fuel Module](https://www.amazon.com/dp/B001234581?tag=rusttoroad-20)
Alternatively: [Holley Inline Electric Fuel Pump](https://www.amazon.com/dp/B001234582?tag=rusttoroad-20)
EFI systems need a return line to send unused fuel back to the tank. If your car doesn't have one, you can use a return-style fuel pressure regulator near the tank.
If needed: [Aeromotive Bypass Regulator](https://www.amazon.com/dp/B001234583?tag=rusttoroad-20)
The Sniper harness is color-coded. Connect power (12V switched), ground, tach signal, and oxygen sensor. Takes 20 minutes if you read the instructions.
Oxygen sensor bung: [Weld-in O2 Sensor Bung](https://www.amazon.com/dp/B001234584?tag=rusttoroad-20) (or have a shop weld it in the header collector)
Turn the key on (don't start yet). The touchscreen will walk you through setup: engine size, timing, idle RPM. Enter your specs. The system does the rest.
Crank the engine. It'll take a few tries while the system learns fuel pressure. Once it fires, let it idle for 5 minutes. The Sniper is learning your engine in real-time.
Drive the car normally for 50 miles. The system adjusts fuel maps based on throttle position, RPM, and oxygen sensor feedback. After 50 miles, it's fully tuned.
- Sniper EFI kit: ~$1,050 - In-tank fuel module: ~$380 - O2 sensor bung: ~$15 - Wiring connectors: ~$20
Total: About $1,500. The cold starts alone make it worth it.
If the engine cranks but won't start, check fuel pressure first. Use a gauge at the Sniper inlet—should read 58 PSI key-on.
If it runs rich (black smoke), the oxygen sensor might be reading backwards. Swap the wires and retest.