Railroaders place to shoot the shit.

2LARRCO has a few -3 units as well. The main diff... Controls. Pretty much the very same power plant, the 16-645 E3B engine, coupled to a main alternator, the AR-10, rectified ta DC... But ta cotrol the 3000-HP to the rails..and six motors, that's where the -3 comes in.

EMD, and WABTEC, plus a few other manufacturers have designs out there, which all make claims as the 'best,' most up-to-date control systems around.

Truth be told... Unless it's a total rebuild, from the motors, trucks, frame, and on up... It's just a standard SD 40-2. Still 3000-HP.
With everything that worked fine for 30+ years. You guys who run 'em know...

One thing ya can't improve upon is the 26-L brake system though. It's THE best, easiest ta maintain, troubleshoot, and repair ever made. Not ta mention the hogger knows exactly how ta run his train when it's 26-L equipped.

Seat of the pants railroading. Real railroading. Upgrading ta the 710 E3B engine wouldn't be a bad idea... Same 2-strole design, bigger/larger displacement engine, same work principle, later alternator...and more fuel efficient.

That's the real reason behind all this rebuilding going on...