The SL-C was designed from the beginning with the idea that the owner/builder knew best about what drivetrain to use. So the engine bay was designed to be as long and wide as possible, to accommodate an incredibly wide range of engines in the car. Most of the Superlite SL-Cs so far have used the popular GM LS-series of V8 engines, as they are lightweight, easily available, have a large aftermarket presence, and are relatively inexpensive for their power output. But pretty much any modern V8 engine will fit just fine, including the new Ford mod motors (and the new 5.0 liter Coyote, which shares a similar architecture) and the late Chrysler Hemis, many Japanese engines, including the popular Lexus V8s, and even Porsche V8s and flat sixes. There is even an SL-C with a 410 Sprint Car small-block Chevy engine with Kinsler injection and stacks!
The following are some pictures of customer engine installations. There are more in the Picture Gallery.
Twin Turbo LS7 (Schwartz Performance)
410 Sprint Engine
Maserati Twin Turbo
Turbocharged 3-rotor Mazda Rotary