Re: 1967 BB A/C fan, 5 blade or 7 blade?
Michael,
Parts in the Chev. parts catalogs are service parts and not always the same as assembly line parts.
The 3931002 fan was a one year wonder, issued to various 1968 Chevrolet models with AC but not the Corvette. The fan has 7 aluminum blades, 18" dia., 3.00" bolt circle, 2 1/4" pitch, and was made by the Schwitzer Company. Each blade was stamped "3931002", "913894" (Schwitzer part #), and a date code. This fan also served as a service replacement as Joe previously mentioned. The 1969 Chevrolet models w/AC (exc. Corvette) and 1969 nZ28's were issued fan # 3937779 (Schwitzer # 914033) which was identical to the 3931002 fan except that the bolt circle is 3.25". Late 1969-1970 Chevrlet models w/AC (exc. Corvette) and Z28's were issued fan # 3947772 which was similar except that the pitch was 2 1/2". The optional assembly line 7 alum. blade fan issued on early 1969 Chev. models w/AC and 1969 Z28's was GM # 3947838 (stamped "H" for Hayes-Albion, "FRONT", and generally, but not always, "84" with a 2 1/4" pitch). The optional assembly line fan issued on late 1969-1970 Chev. models w/AC and Z28's was GM # 3956684 (stamped "H", "FRONT", and "94" (Hayes-Albion part # 159432) with a 2 1/2" pitch).
Dave
Michael,
Parts in the Chev. parts catalogs are service parts and not always the same as assembly line parts.
The 3931002 fan was a one year wonder, issued to various 1968 Chevrolet models with AC but not the Corvette. The fan has 7 aluminum blades, 18" dia., 3.00" bolt circle, 2 1/4" pitch, and was made by the Schwitzer Company. Each blade was stamped "3931002", "913894" (Schwitzer part #), and a date code. This fan also served as a service replacement as Joe previously mentioned. The 1969 Chevrolet models w/AC (exc. Corvette) and 1969 nZ28's were issued fan # 3937779 (Schwitzer # 914033) which was identical to the 3931002 fan except that the bolt circle is 3.25". Late 1969-1970 Chevrlet models w/AC (exc. Corvette) and Z28's were issued fan # 3947772 which was similar except that the pitch was 2 1/2". The optional assembly line 7 alum. blade fan issued on early 1969 Chev. models w/AC and 1969 Z28's was GM # 3947838 (stamped "H" for Hayes-Albion, "FRONT", and generally, but not always, "84" with a 2 1/4" pitch). The optional assembly line fan issued on late 1969-1970 Chev. models w/AC and Z28's was GM # 3956684 (stamped "H", "FRONT", and "94" (Hayes-Albion part # 159432) with a 2 1/2" pitch).
Dave
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