Dude... that's like what my brother is doing to a 1970 Charger except my brother custom made the suspension and beefed up the car's original subframe.
He even had the idea of making a bed like that...

And no, he didn't destroy a good car... this thing was a shell with no drivetrain/interior/windshield/suspension and was rusted out. He custom made the suspension and used the drivetrain out of a late 70s Dodge pickup (440, Auto, Full time 4x4). And yes, that's his 454SS sitting next to it.
More pics of it
here.
This was his other 69 Charger that he bought for $4K, fixed it up and sold for $18K:

See his old 98 GT and 91 or so Ranger STX with factory lift?