He's not saying that the driveshaft is directly in front of the motor, just that the front axle is far enough forward that the 3rd comes up in front of the motor on uptravel.
You know, like most custom built rigs. Either the front axle is hung way out front, or the drivetrain is moved back (according to how you want to look at it, and chassis design)
And unless you are running a super short trans and tcase, that usually leaves you with a really long front driveshaft, making a 2 piece front shaft necessary sometimes