400BB Engine

The biggest bonuses of the 400 B block (413,426, and 440s are "RB" or "raised block" big blocks) are the bores ize...biggest of any Mopar engine, and the casting cores for the main web areas. They are beefier than any other engine. So if you want a big cubic inch, that is strongr than a typical RB or 383, you build a 400 block. There's also a cold weather version cast in mid '71 that came with much thicker cylinder walls. It's known as the "230" block, but not every block with 230 on it is a thick block. It's only between certain dates.