They came with a 318. It had 10 more hp than a 318 in other applications. They had a dual inlet air cleaner, 2 electric fans between the radiator and condenser, and Shelby-specific exhaust manifolds. They also had a hi-stall converter and a 3.90 Sure-Grip rear. Here's an engine pic. You are looking at 100% original belts and hoses there, too.
Dallas