Judging from the pic, plus drawing straight lines across the face of the rotor and the face of the adapter it looks to be the distance of 2 to 3 rotor thicknesses.
I would expect the rotor to be at least 1 in thick, so my guess is 2 to 3 inches.
I think the truck will now have that new wide-track stance. That was popular and a selling point for Pontiac back in the 60's
Will the tires still be inside the fenders, or will fender flares be needed ?
Dan
