Factory wheel/tire size 85 crew long box 3/4 ton?

[Wincks2]

Is a 16 x 6.5 L wheel and LT235/85R16 load range E tire the original from the factory basic combination for this truck? I'm using LT265/75R tires now but one blew and I'm thinking of going back to original style.

I went with LT265/75R tires last year figuring the 265 would put more tire on the road during our icy winters. Only now have I seen that the 265 and 235 are section widths measured in the middle of the tire rather than where the tire tread hits the road. So would there be no safety advantage on ice and snow with the 265 rather than the 235?

Here is how I've reached the conclusion about the above original specs:

The GMC shop manual has a 1985 Truck Wheel Chart with a column headed "Usage" under which are S100, El Camino, Axle, T100, C100, many others including "CKP 200, 300" and "CK 2-300, P300"

Would the last two, "CKP 200, 300" and "CK 2-300, P300" be my truck? Nothing else in the list has a "C" combined with a "200". I'm guessing the "C" and "200" cover my C2500 truck.

Elsewhere in the manual looks like the factory tires were LT235/85R16 with load range E since load range D doesn't go up to 2740 max weight.


Some vin info is:

1 us built
G GENERAL MOTORS
T GMC TRUCK
G GVWR RANGE 8001-9000 HYDRAULIC BRAKE SYSTEM
C LINE AND CHASIS TYPE LINE CONVENTIONAL CAB, CHASIS TYPE 4 - 2, (I THINK THIS MEANS IT IS A C NOT A K)
2 3/4 TON
3 FOUR DOOR CAB
M ENGINE TYPE AND MAKE PRODUCER CHEVROLET, TYPE 5.7L V8 4BBL, MODEL USAGE C-K-G-P, RPO LT9