crankinaway

I figured the seats would be bolted through to frame.

boom50cal

Nope. Seats are bolted into the cab. Reason it takes so little time to pull the cab, just 6 or 8 big bolts and some connectors.

Few ways you can bring a direct to frame ground in. Easiest is through the cab vent at the rear. Can find a grommet back there, if there is one. Or you can drill a hole and use a water tight grommet.