I have a 1939 GMC one half ton AC 302 and a GMC 1946 ec233. Both had the GMC 228. GMC engines are longer than the Chevy eng. Wont fit. I am selling my 46, it is unrestored. My 39 wad a frame off complete resto and is now ready for paint. I have original shop manual if you questions about the GMC i can look up what you need. I will send you link to my temp site in sep thread.