73-87 frame differences

[slotard]

I believe there are some differences in frame height/thickness over the years as well, I don't know how significant they are.

https://www.gmheritagecenter.com/doc...olet-Truck.pdf claims the section modulus for a 73 C10 SWB is 3.06

https://www.gmheritagecenter.com/doc...olet-Truck.pdf claims the section modulus for a 79 C10 SWB is 3.14

https://www.gmheritagecenter.com/doc...olet-Truck.pdf claims the section modulus for an 87 R10 is 3.10

I know I've seen more significant differences for 3/4 tons.

And yes, bumper/core support mounts are apparently a little different as well.