So you know first hand that new cars came with engines that were already bored and turned crankshaft BS. I caught my mistake on spelling. If you notice several others have agreed on off setting of the rear seal.
Yes and blocks were clearly marked showing an over bore. Common knowledge, codes are stamped on block's
In 1973 tons of 340 were 20 over. I have pulled many 1973 factory 340 at yards that were 20.