May people that blow thier motors due to a "lean condition" do it in fact due to excessive timing advance. When you compensate to a large degree with an SFAC, you're throwing off the ECU's calulated load%, which in turn causes it to advance timing. Under less load, more timing is acceptable and desirable. Under high loads, less timing is needed to stave off preignition. When the ECU thinks load is around 70% due to a modified MAP output when it in fact should be nearly 100%, expect to see 30 someodd degrees of timing advance. WOT, uphill, whatever. You'll knock, and in turn break things no matter how perfect your fuel curve is.

People blow these motors because of detonation. They tear it down, see a cracked piston, and know that the motor was detonating. However, most people don't seem to realize that detonation is not just caused by lean fuel mixtures (which really cause HEAT, and HEAT causes preignition) but by many things including improper timing curves. So yes, many people here that have have blown their motors have done it due to improper timing curves, they just don't know it.