Panic's response brings up an interesting and obvious question: Why did GM, knowing better in the 1960s, design and manufacture a brand-new series of six-cylinder, inline engines in the way that they did?
Why, in particular, did GM continue to manufacture heads with siamese ports in a new series? This is not just "1950s" technology, but 1910s! The rest of it could be chalked up to "economy" and an emphasis on low- and mid-range torque for hauling loads, but the siamese ports, in 1963, make no sense to me.
God's Peace to you.
d
Inliner #1450
