9 or 7 Fin Valve Covers
03-30-2011, 10:54 AM
#1
Instructor
Thread Starter
9 or 7 Fin Valve Covers
When were 9 fin aluminum valve covers used? And when did 7 fin covers start in production. Thanks.
03-30-2011, 11:04 AM
#2
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ALL 56 Corvettes with the optional 2x4 carb engine had 9fin covers.
ALL 57 Corvettes with ANY optional engine got 9fin covers up to about mid production (around Dec 56) and then changed over to the 7fin covers.
Fairly early in the 57 FI cars with 9fin covers, the LEFT cover got a big notch machined in the upper fin to facilitate clearance of the FI air meter. It is generally believed that because of this notch in the left FI valve cover a decision was made to eliminate the upper/lower fins on all valve covers. Thus, the change from 9 to 7fins.
Tom Parsons
ALL 57 Corvettes with ANY optional engine got 9fin covers up to about mid production (around Dec 56) and then changed over to the 7fin covers.
Fairly early in the 57 FI cars with 9fin covers, the LEFT cover got a big notch machined in the upper fin to facilitate clearance of the FI air meter. It is generally believed that because of this notch in the left FI valve cover a decision was made to eliminate the upper/lower fins on all valve covers. Thus, the change from 9 to 7fins.
Tom Parsons
03-30-2011, 01:51 PM
#3
Instructor
Thread Starter
Thanks Tom
