F.R.
I don't know how they're measuring engine length, but I measure the FEs we've got here at 30" from block face to the nose of the (stock) water pump. Maybe your numbers include the flywheel.
At any rate, with an FE we've got about 1.75" clearance between the water pump and the front chassis vertical "X". At a minimum, I'd prefer 1/2" clearance to install alternator belts with the 460, which
has been installed in our cars a couple of times.
Ground clearance should be fine if you can find an
oil pan that's 9" from the crank centerline to the bottom of the pan. The reason I'm not giving an actual pan depth is that I don't know how much the 460 block extends down from the centerline, if at all.