welcome to the site! Make sure to post in the welcome wagon and introduce yourself and your truck!
My trucks are newer so, I am not real familiar with your year (nor the COE) but, there are a number of threads on here talking about older cabs on newer frames, COEs included.


Mike
1955 Chevy 6400 ex-flatbed (no bed now!) sold September 2023
In the Stovebolt Gallery
1958 Chevy 6400 flatbed W/dump
In the Stovebolt Gallery
1959 Chevy Suburban Owned for almost 20 years, Daily Driver -- sold May 2016
In the Stovebolt Gallery

Sufficient unto the day is the evil thereof