Here's what I think your numbers tell us...maybe one of the Canadian guys can confirm I got it right as I'm guessing that's where it was made...
Chassis Serial Number (VIN) CA6C584905
CA = Plant (I believe this is a non-USA plant...made for export)
6C = 6500 Series (174.5" wheelbase)
58 = year
4905 = unit number
Engine Serial Number F527LB
F = Flint
5 = Month (May)
27 = Day
L = 261 6-cylinder
B = ??? look at this letter again, could it be an "E"? This letter indicated what RPO's were added to your truck.
Did your truck come with an automatic transmission or Air Over Hydraulic Brakes?