Oh well...no other takers so I'll do it.
CS1570CPC4690A
C = Conventional cab
S = Six cyl
1 = 1/2 ton
57 = cab to rear axle dimension of 42 inches
0C = Step side box
P= pontiac Assembly Plant
C = 1967
4690 = sequence number
A = is GVW range 6000 and less
It's a 6 cyl 1967 GMC short box step side, by whats posted
CE1570DPC2842A
C = Conventional cab
E = Eight cyl
1 = 1/2 ton
57 = cab to rear axle dimension of 42 inches
0D = Wide side box
P= pontiac Assembly Plant
C = 1967
2842 = sequence number
A = is GVW range 6000 and less
It's a 8 cyl 1967 GMC short box fleetside, by whats posted
That's why there is difficulty making a GMC Vin decoder, different plants did the vins differently.