A friend has a '72 Malibu 400, has the "400" badges on the fenders. Underhood is the LS-3 402 inch big block and emissions decal showing 402 cubic inches.
It wasn't an accidental overbore, the 396 had suffered from valve shrouding with the bigger valve performance heads. Increasing the bore helped alleviate that problem, made it easier to lower compression, and also brought the engine back in line with comparable 400 inch B-O-P offerings.
You meant 348? 428 is a Pontiac or a Ford.
And to keep this on topic:
Favorite Mopar myth is that Chrysler invented the Hemi.
Hemi engines were designed and used in early Grand Prix cars in the early 1900's, well before Chrysler existed. One notable example was the 1907 Fiat 130:
(Yes that's right...Fiat was racing with hemis 18 years before Chrysler existed! :D )
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