71 Chevelle 2 door 454 Wagon info needed

[L78 ELCAMINO]

In the mid sixties my father worked at a tool and die shop in Detroit, Fridays after work he and a few of his pals from work would ride up and down Telegraph Rd and Woodward Ave in my dads 65 Chevy Suburban trying to drink Strohs beer out of business. After repeated occasions of being left in the fumes of high octane fuel by what he called "snot nosed brats with ten times the HP as IQ", my dad ordered and took delivery of a 66 Suburban that came off the lot of Tenneyson Chevrolet in Farmington Michigan with a 427/425 big block mated to a stout Turbo-Hydro tranny. Before my dad passed away I picked his memory to see if he could remember if it was factory built or dealer converted. It did come with a factory warranty as it was always in the shop having the center carrier bearing replaced, which was the reason he traded it back in a year later for a 67 427 Caprice. Was it possible that it may have been a special order COPO Suburban? Or if dealer converted how could that be explained to GM with the constant warranty repairs? My older brother was relentless in always wanting to use dads suburban on weekends to leave his tricked out and very quick 55 Chevy in the driveway. Would the factory actually have built such an animal if the dealer had the right connections and knew the protocol to pull it off? Possibly a case of the right hand not knowing what the left was doing similar to the recent Berger/GMMG Camaro venture. I witnessed more arguments between my parents during that year then the entire rest of my childhood. Anyone ever see or hear of something of a similar nature?
Thanks