They are 99% the same. I realized this past weekend that I've had an L59 the whole time I thought it was an LM7. Only differences are more injector flow (33 lb/hr vs 22.5-28, depending on the year iirc), different fuel injector connectors (EV6, I believe, vs minitimer), and a few differences in the ECU. Depending on the year, it got a sensor to detect the ethanol content of the fuel, and also depending on the year, it kept return rails longer than the non-flex fuel motors did.
Besides that, it is literally the exact same motor.
