The S550 Ford Mustang Shelby GT350 is going to go down as one of the all-time greatest muscle cars. With a uniquely flat-plane crankshaft, 5.2L “Voodoo” V8 engine, the S550 Mustang GT350 had an attitude that was unmatched by anything we saw from its crosstown rivals. But the origin story of what led to this GT350 getting 900 horsepower is also a story of why the GT350 is to be approached with caution. This Barra-engined Shelby GT350 was created due to an unfortunate incident with the Voodoo 5.2 V8 engine. As TheDudeinBlue stated in his YouTube video, Adam LZ found himself in an unfortunate sit…