MS3Pro ULTIMATE GM LS 58x Plug and Play includes an MS3Pro ULTIMATE ECU, TunerStudio software and the most rugged & durable GM 58X custom harness available. 
Experience the MS3Pro ULTIMATE.
Developed from the MS3Pro 1st Gen platform, the Ultimate brings NEXT LEVEL capability to MS3Pro’s staggering feature set beginning with a new high quality aluminum IP65 rated, water resistant enclosure.  The MS3Pro ULTIMATE provides 10 programmable peak and hold injector channels for driving any saturated or peak and hold injectors as well as loads of additional I/O eliminating the need for any other controllers, saving you unneeded complexity and weight.  Out of the box ready for naturally aspirated and boosted applications with on-board 4-bar MAP and barometric pressure sensors, MS3Pro ULTIMATE was designed to handle your engine combo without breaking a sweat!
No need for a separate data acquisition system, the MS3Pro ULTIMATE will log up to 64 channels, conservatively, at 200hz. The advanced TunerStudio software provides an intuitive, straight-forward tuning experience for pros and enthusiasts alike with best in class self-learning, self-tuning fuel table strategies to assist you.
–Visit MS3Pro ULTIMATE product page for a complete features list– Experience for yourself why more and more racers and performance enthusiasts are recognizing and choosing MS3Pro over the competition.
The MS3Pro ULTIMATE GM LS 58x Plug and Play Harness is the highest quality, best value option for LS Motors in the industry today.  Save your hard earned time and money while experiencing the virtually limitless feature set of MS3Pro ULTIMATE Engine Management System.  Simply choose your injector style from the drop down menu!
Professionally engineered and easy to install,  fire up your engine on day one!   All wiring is composed of TechFlex woven, self-extinguishing wrapped hi-temp TXL & GXL automotive grade wire with OEM Delphi & TE connectors. Reach the battery under the hood or in the trunk with 4 gauge power & 10 gauge ground wires.  All relays and fusing live in a single, waterproof fusebox and the fuel pump wiring / relays / fusing is big enough for pumps that can handle 1000whp or more right out of the box (10ga wire, 30amp circuit).  Additionally, all of the available I/O of the MS3Pro ULTIMATE are brought out in the harness to make expansion as easy as possible regardless of the featureset you’re planning to use, allowing for killer features like traction control, bump box, table switching, flex fuel, and more.  This harness was designed with room to grow!  And did we mention it’s show-quality-drop-dead-gorgeous?
This harness also is designed for optional automatic transmission control using the AMP EFI CAN transmission controller; Just plug in our transmission controller using the proper sub-harness (for 4L60E or 4L80E) and you’re ready to control your trans!
Required connections:
Constant Power
Constant Ground
Switched Power
Starter
Alternator light
Suggested extra connections:
Fuel Pump Power
Tachometer Signal
The MS3Pro 58x GM LS Plug and Play Harness is configured for a cable operated throttle body. The included connectors are set up for an LS1 style throttle position sensor and IAC valve. Four barrel style or independent throttle body setups may require modifications to the harness.
Note that the alternator connection is designed for high mount alternators such as Corvette and truck setups. Low mount alternator setups, as well as other aftermarket accessory drives that do not have the alternator high on the driver’s side, require our alternator extension cable.