Sam I would have to agree with you
I figured the car guru didn't put forth much effort in the truck department & let the numbers slide in the dumpster

I find it funny when these guys claim these numbers & actually no one knows

The guy I'd been talking with displayed every view & what I did see was the wrong angle & length on a in cab filler neck

131" wb Conv cab = Reg Cab with 8' bed
165" wb Crew cab = the farmers son I know is probably right

I know I've seen a bunch of tow,tug,dump,roll,sweeper & host of other commercial style trucks with an in cab & that is a given by it being available in the parts books up into the 80's

Dealer installed only or truck body vendor it seems possibly factory through the dealer commercial Truck department