I have an AIR pump with no numbers stamped on it--was that way when I purchased it but inside when it was rebuilt by B. Hodel it said 1973 (has black plastic centrifugal filter). The pulley that was attached to it# is 3927116AU. I will try to post pictures of the manifold tubes--does anyone know what they look like for a 1973. Trying to figure out if they are all the same year. Bought them along with other parts for my 71 and then found out they were incorrect.
-
-
Re: AIR pump, Pulley and manifold tubes. What year?
Paul-----
The AIR manifold tubes assemblies ("trees") were exactly the same for 1971 LT-1 and all 1973 small block. These are the "crimped" style tubes with smooth, "blackish" organo-phosphate or "black zinc" finish. The left side was GM #3905297 and the right side was GM #3877480. The left side tube was also used for all 1967-72 small blocks with AIR and the right side tube was also used for all 1966-72 small blocks with AIR.
The external configuration of the 1971 LT-1 AIR pump and the 1973 AIR pump are identical except for, of course, stamped numbers and, possibly, the centrifugal filter ("fan") color. 1971 definitely used the "white" centrifugal filter. I think that by 1973 the black filter was in use. Otherwise, though, the pump configuration is the same for both years.
Both 1971 LT-1 and all 1973 with small block used AIR pump pulley GM #3917234 in conjunction with pulley spacer GM #3933185. The spacer is 3/4" thick and is installed between the pulley and the pump hub.
The GM #3927116 pulley was used for many 1968-69 passenger, Chevy II and Camaro applications and also a few 1970-75 applications. However, it was not used for a Corvette application.In Appreciation of John Hinckley
Comment