Originally Posted by B1MAXX
the only factory engine with a bigger bore is a 460 Ford. The 454 is 4.25 puke that is why there are so many aftermarket blocks for them. The 396/454 engines with rectangle heads have huge bore notches from the factory, the 396's are only 4.096. The un-notched oval port engines are only a 2.06 intake valve...........advantage Mopar. Bigger bore , larger valve. And when they did settle on a 4.25 bore they knew the only way to get a big valve un-shrouded was hemispherical.



Was not aware the OP was referring to factory blocks. I would assume since he is talking about 555" engine size on a Mopar site. So in my feeble mind we are talking aftermarket parts thus making factory dimensions a moot point in this discussion. I get it that Mopar guys have to defend the mother ship at all costs but in the instance of this discussion its irrelevant what the factory dimensions are.

Ask anyone who is a Chevy drag racer which engine will run better a 555 or a 565. Anyone with any experience will pick the 565 all day long and twice on weekends. The difference, the bore size..

"I am not ashamed to confess I am ignorant of what I do not know."

"It's never wrong to do the right thing"