They are in fact different "pumpkins" fitted to different style housing and do not interchange. Here's a couple of internet screen grabs just for visual reference. Hope this answers the question.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
The hole in the truck housing is round- - - -the 56 car housing has an oval shape, and I'm pretty sure the axle length, spline diameter, and number of teeth is different, also. Passenger car axle flanges have 5 lug studs- - - -trucks have 6. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
