How well do they perform? I'm having a hard time finding LA blocks so it looks like I'm going with a Magnum block if I want to build a 360. Only other 2 choices seem to be the stock heads (crack prone) or the new cast-in-China EQ heads (poor flow compared to the original Australian EQ heads). I'd like to end up with an engine that can run mid to low 11's in a 3000 lb car with good suspension and torque converter. How much work would the Eddy's take to support that? Also, can anyone recommend a good head porter that doesn't have a year lead time?