57 timing tab

[Greg K.]

I've found some timing chain covers with different timing tabs. Some have A-O and others have A-O-R for the advance-retard readings. Does anyone know if the 57 came with either or if it was truly one way or the other. Would appreciate some clarification.

[Wayne L.]

Re: 57 timing tab

I believe A-0 is correct for the 1957 timing tab. The A-0-R tab started being used possibly in 1964??????

[David L.]

Re: 57 timing tab

Enclosed are 2 photos of my 55-61 timing cover (in very poor condition) as well as a sketch of the timing cover tabs which is based on research over the last 30+ years.

Dave

[David L.]

Re: 57 timing tab

Here ia a photo of a timing cover from my 1966 Corvette w/base 327. The 1967 Corvette w/base 327 cover is the same except there were date codes stamped on the cover. In years past I have had these covers stamped "12 66" and "1 67". I believe that "early" 1966 models had the small tab like the Late 1964 & 1965 models.

Dave

[Greg K.]

Re: 57 timing tab

Dave, I'm a little confused now. Your last photo shows the timing tab A-O-R on your 66, but your sketches show that should be an A-O.

[Greg K.]

Re: 57 timing tab

Or are you saying t=he 66 has A-O-R but with a notched tab vs a ramp?

[David L.]

Re: 57 timing tab

Dave, I'm a little confused now. Your last photo shows the timing tab A-O-R on your 66, but your sketches show that should be an A-O.

Greg,

My sketches are for 55-61, 62-E64, and L64-65 timing tabs, no sketch for the 66-67 tab.

Dave

[David L.]

Re: 57 timing tab

Greg,

Here is a scan from my research on timing cover tabs. The sketch of the 66-67 tab is on the lower left. The parts numbers listed are for service timing covers, not necessarily the same as production timing covers.

Dave

[Greg K.]

Re: 57 timing tab

This has been extremely helpful Dave. And makes more sense to me too. Thanks so much.