"LA" engine?

I just looked at my copy of How to Hot Rod Small Block Mopar Engines by Larry Shepard. In chapter 1 it states"As far as performance is concerned, the real story begins with the introduction of the 273 LA engine in 1964. As an LA (lightweight A) engine, it was lighter than the original 1956 engine. It was manufactured using modern, lightweight casting techniques based on a new coring process at the block foundry. The "old" "A" engine was too large and too heavy to fit into many of the upcoming vehicles. The lightweight "A" (LA) was also narrower because of the valves-in-line wedge style head that was used...........................But the key to the LA engine was lightweight and smaller size."

Believe what you want my friend. I'll stick to the facts written by the experts and quoted from Chrysler engineers themselves. tmm