There was another discussion on the heads being the same.

http://www.patricksantiquecars.com/chevy-gmc-auto-parts.html#chevy15


FIlling Station catalog lists the 206-216 and all GMC 1939-1959 (except the 302) as the same insulator as 23/4" bolt spread and 1.5 ID which matches my parts as mine was larger than the 29/16" mentioned prior. Part # FS-106

They list the 235, 261 and GMC 302 as the same part with the 215/16" bolt spread 111/16 ID. Part # FS-238

Last edited by showkey; 08/04/2017 2:30 AM.