396 Cam question

[Dwight Southerland]

Originally Posted by Alan Nyhus

Alan, the '65 396-425's (Corvette and full size Chevys) had a mechanical lifter camshaft with .497/.503 lift. This was a different camshaft than the '66 and later 396-375's and 427-425's (.520/.520).

Same camshaft, just a clerical difference. If you look at the original (1965 version) of the NHRA Tech Bulletin, the part number is listed for the camshaft and it is the same as all the later L72 and L78 engines - 3863143 with a casting number of 3863144. If you research any and all of Chevrolet's documentation, whether it is parts manuals, production specifications or whatever, the 1965 engine used the same camshaft as every other 396 solid lifter engine built between 1965 and 1969 with lift specifications of .520"/.520". Chevrolet power manual lists the specifications of the same part number camshaft as "net lift" of .500" with lash settings of .024" intake and .028" exhaust. Maybe Chevrolet provided NHRA with net lift numbers in 1965, who knows. Regardless, the .497"/.503" numbers are in the 'Guide and we have to live with it.

Also, the hydraulic camshaft used in the 396-375 Z16 Chevelle is the same camshaft used in the 396-350/360 hp engines and 427-385/390/400 hp engines in 1966-1969, again with slightly different clerical numbers.