Official Difference btween the 396 and 402 BB Because you asked.

[LONGHAIR]

I have heard the flood thing before too, but I'm not so sure that I buy either of the "damaged" block theories.
If the bores were rusty, the rest of the block would have been too, lifter bores, main saddles, etc...
If the bores were "crooked" they would have gone back to the supplier....

They couldn't possibly have been "sitting on" that many blocks. If that really had been the case, they would have either used them and just said nothing, sent them back to be "recycled", held them as warranty replacements, etc. They would not have spent the time/money to re-bore them and create new pistons to make it happen. Plus, they would have gone back the "standard" 396 configuration when the "supply" of these "bad blocks" was exhausted.

I think the 400 in small block form was the issue. The smallest "big block" needed to be bigger. The 400 came out in the same year, coincidence?

Now why they used the 400 name badge for trucks? and 402 in cars? Who knows?

[GuyO]

Originally Posted by LONGHAIR

I have heard the flood thing before too, but I'm not so sure that I buy either of the "damaged" block theories.
If the bores were rusty, the rest of the block would have been too, lifter bores, main saddles, etc...
If the bores were "crooked" they would have gone back to the supplier....

They couldn't possibly have been "sitting on" that many blocks. If that really had been the case, they would have either used them and just said nothing, sent them back to be "recycled", held them as warranty replacements, etc. They would not have spent the time/money to re-bore them and create new pistons to make it happen. Plus, they would have gone back the "standard" 396 configuration when the "supply" of these "bad blocks" was exhausted.

I think the 400 in small block form was the issue. The smallest "big block" needed to be bigger. The 400 came out in the same year, coincidence?

Now why they used the 400 name badge for trucks? and 402 in cars? Who knows?

I read that the 400 badge was due to Federal emissions regulations prohibiting engines larger than 400 ci.