Near as I can tell, it's basically the 389 style hood and sleeper(s) with the newer style driving cab.
With the old style cab, the stacks lined up with the sleeper, not typically protruding past it on either side - with this wider cab, it looks like the stacks do protrude beyond the sleeper on each side. Not sure on that of course, but that would be a design fail in my opinion.
It doesn't look bad, but the hood and cab don't really match - the windshield especially looks weird in this setting. A decent successor to the 389 in my opinion - it could've been much worse!
The odd hood and cab combo immediately brought to mind this photo I came across years ago. Not my photo.
Someone back in the 70's or 80's built this beast - a White cabover cab with the drivetrain reconfigured and a hood added.
Pretty similar combo of the wide windshield and the narrow hood...