I havent had any issues with Indy's geometry, or Edelbrock's. Both have the same "mass production line" assembly problems. Geometry is a result of a bunch of variables that get put together. And adjusting it is common. If you didnt with iron heads, it's because you're not looking, or overlooking something...lol. I dont think the vast majority of car owners need or really want 550hp and the associated issues and compromises that come with it. The question of "375" plus bolt ons is very valid. A performance rebuilt 440, on pump gas, iron heads, stamped rockers, and up to date cam and intake will make more than 450 with stock exh manifolds if parts are chosen properly. Not hard, very reliable, hydraulic cams, etc. Headers on that same engine would add another 20-30hp without loss of drivability. That's honest low 12/high 11s in a typical E body and a suspension/tire to drag race. High 12s on radials. That's why I tend to say budget and et/goals first..Then worry about the parts choosing. Now there are better options than factory stuff, for slightly more $$. But many guys don't need to spend the coin on roller rockers, coated headers, X pipes, H beams, etc to run as fast as they ever would want to.