disabled access re 2006 GMC Sierra Crew Cab

[d john pickering]

Where can I find the difference in the "step in" distance off the ground for the 2 wheel drive 2006 crew cab vs the 4 wheel drive when I can't find the actual truck to measure ?
I was told that the two wheel Classic Sierra/Silverado Crew Cab would be easier for my disabled Dad but can't find one to measure.

Many thanks, Dave