http://www.prolineracing.net/engines/plr-670ci-4000-hp

Is it a Ford?
Is it a Chevy?

The answer is simple. It's a completely custom 5.000" bore center Pro Line Racing 670ci engine.
A few facts about this engine:

BBC/BBF crank won't bolt in it.
BBC/BBF heads won't bolt on it.
BBC/BBF oil pan & timing cover won't bolt to it.
There is no provision for a distributor.
Since it's inception in 2008, the Pro Line Racing 670ci engine has proven itself to be the most competitive and reliable choice for Outlaw 10.5 racing. The custom billet aluminum block and heads offer the ability to handle upwards of 4000hp! The billet cylinder heads were designed specifically for water to pass through them, which makes the PLR 670 perfect for your gas powered 10.5 car!