Holley · Part 550-927
Holley EFI Terminator X Max MPFI Kit - Gen III 4.8/5.3/6.0 Truck LS, 24x / 1x, Multec 2 Injectors, DBW + 4L60E/4L80E Transmission Control
GM Gen III LS truck engines (4.8/5.3/6.0) with 24x crank reluctor; Multec 2 injector connectors; drive-by-wire throttle body; controls GM 4L60E or 4L80E automatic transmissions. The classic junkyard truck-engine swap kit.
$2,199.95
In stock in Corona. Free shipping in the continental US, or collect it at the shop.
No returns or exchanges on third-party hardware — the manufacturer’s warranty is the warranty. Returns policy
Emissions
What it is and what it fits
GM Gen III LS truck engines (4.8/5.3/6.0) with 24x crank reluctor; Multec 2 injector connectors; drive-by-wire throttle body; controls GM 4L60E or 4L80E automatic transmissions. The classic junkyard truck-engine swap kit.
What it does
- One ECU runs engine, DBW throttle and 4L60E/4L80E shifting - no separate trans controller
- Harness plugs into factory early-truck Multec 2 injectors
- Handheld wizard sets up base engine and trans calibration
- Boost and nitrous control built in for turbo truck-engine builds
Fitted and tuned on our hub dyno, or shipped to you
Buy it and fit it yourself, or have us do it. We install, wire and calibrate Holley engine management in our Corona shop and tune it on a Mainline ProHub hub dyno, with the full sheet at the end. Shop labor is $265 an hour, quoted against your car; the calibration is priced on the standalone tuning page.
It is in stock in Corona and ships free anywhere in the continental US. Alaska and Hawaii are quoted by phone. If you would rather collect it, or have it waiting here for your install, say so at checkout.
Specifications
Holley 550-927
- Brand
- Holley
- Part number
- 550-927
- Injector drivers
- 8, sequential, high-impedance (saturated) only - will not drive low-impedance injectors
- Ignition outputs
- 8 coil-on-plug outputs (direct drive of LS smart coils)
- Programmable inputs
- 4 (12V, ground, 5V, frequency)
- Programmable outputs
- 4 (ground / PWM)
- MAP sensor
- Internal 1-bar; external 2+ bar via GM 12592525 + Holley 558-416 adapter
- Wideband
- Bosch LSU 4.9 closed-loop control (LSU 4.2 not supported)
- Fuel learn
- Real-time self-learning base fuel table
- Boost control
- Boost vs time / gear / RPM / speed, with safeties
- Nitrous control
- 1 channel wet or dry, progressive or non-progressive, rich/lean safeties
- User tables
- 4x 1D, 1x 1D per-gear, 4x 2D, 1x 2D per-gear
- ECU size
- 7.45 x 4.1 x 1.66 in; diagnostic LEDs must face up
- Throttle control
- Drive-by-wire
- Transmission control
- GM 4L60E / 4L80E
- Recommended pedal
- GM 10379038 (not included)
Questions
Before you buy
Is this the price other dealers charge?
Yes. $2,199.95 is the price authorised Holley dealers advertise, and DEFI is an authorised Holley dealer. Shipping in the continental US is free on top of that.
Will it fit my engine?
Read the fitment above against your engine, sensors, injectors and throttle before you buy. If anything is unclear — a part number, a connector, a transmission — call us first. That conversation is free; a wrong unit is not.
Can I return it if it is the wrong one?
No. There are no returns or exchanges on third-party hardware once it ships — the manufacturer’s warranty is the warranty. That is why we would rather answer the fitment question on the phone before you order.
Is it street legal?
Holley publishes no CARB Executive Order for this kit. It is sold for racing and for vehicles that are not emissions-controlled: it is not legal on a pollution-controlled vehicle registered in California, and a vehicle running it will not pass a smog inspection. We are not going to imply otherwise.
Can you tune it for me?
Yes. We calibrate Holley standalones on our hub dyno in Corona, and we can review logs remotely if the car is somewhere else.