My manual suggests front torsion ratings of 1250lbs for both 1/2 ton and 3/4 ton. There was an optional 1500lb front torsion spring for both. Rear coil ratings of 1250lb for 1/2 ton and 2000lb for 3/4 ton.
The GM heritage manual details additional spec ratings, but does clearly suggest fronts are the same and rears are different.
