Model Information: Kato introduced the SD70 model in 2003. The first version was the SD70MAC. They followed up in 2005 with the SD70M. In 2006 they added the 'Flat Radiator' SD70M version. In 2009 they introduced the SD70ACe and revised the SD70M. All versions of this model share the same internal mechanism and only show minor differences in the shell. The internal mechanism was heavily revised/evolved in the 2009 release.

The revised versions are typical modern Kato release with a split-frame design, dual flywheels, chemically-blackened wheels and up-gradable to DCC with a drop-in decoder. They pull well and run quietly. The have very nice details like separately applied (rather than molded) hoses. Due the the 6-axle configuration, they do not run well in curves of less than 11 inches.

DCC Information: Models accept the following plug-in decoders:
- Digitrax DN163K1C: 1 Amp N Scale Mobile Decoder for Kato N scale SD40-2 locos made from year 2006 onward.
- Digitrax SDN144K1E: 1 Amp N Scale SoundFX/Mobile/FX3 Function Decoder for Kato SD40-2 and similar locos.
- TCS K1D4: 4 Function Drop-In for Kato N-Scale EMD SD40, EMD SD70MAC, EMD SD70/75M, GE C44-9W, GE AC4400W, Athearn F45.
- TCS K1D4-NC: 4 Function Drop-In for Kato N-Scale EMD SD70ACe, EMD SD70M, EMD SD40-2, and GG1.
- MRC 1644-2: N-Scale Sound Decoder for Kato SD70MAC & AC4400
- MRC 1960: N-Scale Sound Decoder for Kato SD45/SD70MAC/AC4400

Prototype History: The EMD SD70 is a series of high-powered, single engined 4,000hp to 4,300hp, diesel-electric locomotives produced by Electro-Motive Division (EMD). All locomotives of this series are hood units with C-C trucks. Production commenced in late 1992 and since then over 4,000 units have been produced. The most produced models of the series are the SD70M, SD70MAC and SD70ACe models. All SD70 models were delivered with the self-steering radial truck HTCR , then from SD70ACe and SD70M-2 models, with non-radial HTSC truck. The radial truck allows the axles to steer in curves which reduces wear on the wheels and railhead.

The SD70ACe AC-traction diesel locomotive (most in the industry simply call them SD70 "Ace" or "Aces") is the successor to the older SD70MAC. It was first introduced in 2004, and has been in production since 2005. It was originally designed to comply with EPA Tier 2 locomotive emissions regulations. Beginning in 2012, newly built SD70ACe's were EPA Tier 3 compliant. SD70ACes are equipped with EMD's 16-710-G3C-T2 prime mover, rated at 4,300 horsepower (3,200 kW); later Tier 3 models are rated at 4,500 horsepower (3,400 kW). The model is still in production as EMD's primary long-haul domestic locomotive.
Although mechanically similar to earlier SD70 units, the SD70ACe rides on a new underframe and uses mostly new sheet metal above the frame. Electrical cables and air lines have been routed beneath the walkways on opposite sides, allowing easier access for maintenance. Continuing the designs of the SD80 and SD90 series, the radiator on the locomotive is nearly as wide as the cab, the center hood section is a step down below the roofline, and the dynamic brakes have been moved to the rear of the hood. The SD70ACe uses the cab design of late-model SD90MAC-H units, which uses rectangular window glass and is externally different from the two cab variations used on earlier SD70M and SD70MAC units. In 2008, EMD standardized the isolated cab on subsequent SD70ACes after non-isolated cab units were restricted from leading on BNSF Railway due to excessive cab vibration. Purchasers included ArcelorMittal, BNSF Railway, Canadian National Railway, CSX Transportation, Ferromex, Kansas City Southern Railway, Montana Rail Link, Norfolk Southern Railway, CVG Ferrominera Orinoco, Union Pacific Railroad, Quebec North Shore and Labrador Railway, BHP Billiton, and shortline Arkansas and Missouri Railroad.