I found this post at
www.nastyz28.com regarding the alt fans................
"The alternator fan with the "hook" (a.k.a "shark tooth fan"
as shown in the link below was used on 1968 Z28's as per Jerry MacNeish's book entitled "The Definitive 1967-1968 Camaro Z28 Fact Book" as shown on page 14. According to my parts catalog research the GM part number is 1969448 and was used on the following 1968-1969 alternators: 1100796, 1100810, 1100818, 1100845, 1100847, and 1100849. According to Chevrolet Parts History GM # 1969448 was discontinued in May 1969 and replaced with GM # 1966990. HOWEVER, apparently fan # 1969448 continued to be used on the production line as I have seen this same alternator fan on many original 1970 Z28's.
The only difference between the 1969448 fan and the 1966990 fan is the "hook" on the largest blade.
There is a Chevrolet Dealer Service Technical Bulletin (68-T-63) dated Sept. 13, 1968, about noise complaints stating that "The majority of complaint vehicles were equipped with the Delcotron high speed fan, #1969448, which was found to be dynamically unbalanced."
For those who have ORIGINAL alternator fans on their 1970 Z28's does the fan look like the 1969448 fan with the "hook"?....."
Also, Mike Steitz (70'Camaro Judge/Camaro Nationals) reported that he had never seen a "hook" style fan on a 70 Z-28 !!!!!!
__________________
Chuck Sharin
[email protected]
Auburn,WA (30 miles South of Seattle)
70 Camaro R/S Z-28, L-78, R/S SS
69 Camaro COPO "recreation"