When enthusiasts talk about a tunnel-port 427 Sideoiler engine, it’s usually in the context of Ford’s glory days in racing. This massive, high-flowing V8 withstands high-rpm bashing. So, finding one swapped into an H-code Mustang that originally ran on an intermediate-block 351 Windsor is mind-blowing.

Ford Engineering built this engine as a workaround in 1967 when NASCAR banned its intimidating 427 SOHC in response to Chrysler’s complaints. The tunnel-port intake uses big round intake ports and centered push rods to greatly improve the engine’s airflow, especially in the Money Trap’s dual quad version. In addition, the Sideoiler design incorporates a special oil channel on the engine block’s left side, instead of in the center. The oil is then delivered directly to the crank.

After Ford combined these two designs, it had a fearsome double whammy of an engine. It boasted a compression ratio of 12.5:1, a tolerance of 7,000 RPMs, and an output of around 600 hp.

While American Mustangs hasn’t revealed whether the Money Trap has had a few runs on the dyno, the stats alone are convincing. So while we can’t be sure whether the tunnel-port 427 Sideoiler ultimately bankrupted its previous owner with a name like Money Trap, we think it’s money well spent on this classic car