Need photo of an original 65 L76 365hp timing tab

[William G.]

Does anyone have a photo of an original 65 L76 365hp timing tab? I want to be sure I have the correct cover. Thanks, Bill Gould

[Jim S.]

Re: Need photo of an original 65 L76 365hp timing tab

The Tab on the right is correct for a 66 L79 . I'm thinking it is correct for your application as well.

At least with the picture posted, others more knowledgeable than I can confirm or deny.

[Alan D.]

Re: Need photo of an original 65 L76 365hp timing tab

The tab on the left seems to match mine, however that's for a 64FI but original.
Here are some pn, but that does not mean the cover number did not change, since these numbers are from a 1971 book.

[Joe L.]

Re: Need photo of an original 65 L76 365hp timing tab

The tab on the left seems to match mine, however that's for a 64FI but original.
Here are some pn, but that does not mean the cover number did not change, since these numbers are from a 1971 book.

Alan------


The GM #3885039 shown is a SERVICE-only timing cover. It has dual timing tabs for both the 6" and 8" balancers. Depending upon application, one of the tabs is removed prior to installation. Neither of the tabs are exactly like the original PRODUCTION tabs.

[Joe L.]

Re: Need photo of an original 65 L76 365hp timing tab

Here's a a few photos of the tab configuration on a GM #3885039:


s-l500.jpgs-l64_004.jpgs-l64.jpg

[Alan D.]

Re: Need photo of an original 65 L76 365hp timing tab

Back to William's question "photo of an original 65 L76 365hp timing tab" Is one shown above?
Assume the part numbers shown in the GM Cat are "service replacements" and not the original part numbers or the original configuration or the production part either?
Now for my question, is the one in my post look to be original? Did have engine apart in 70's so may have changed. It does not have any remains of the dual tab however.

[Joe L.]

Re: Need photo of an original 65 L76 365hp timing tab

Back to William's question "photo of an original 65 L76 365hp timing tab" Is one shown above?
Assume the part numbers shown in the GM Cat are "service replacements" and not the original part numbers or the original configuration or the production part either?
Now for my question, is the one in my post look to be original? Did have engine apart in 70's so may have changed. It does not have any remains of the dual tab however.

Alan------


There were slight variations of these tabs used over the 1962-68 period. I've lost track of the nuances. However, the original tabs were "flat", not slightly arched. So, if one finds a small block timing cover with a flat tab spaced for an 8" balancer, it's from one of the 1962-68 SHP engines (Corvette or otherwise). As far as which year or which portion of a year, I just don't recall.

The slightly arched tab seen on the left in the first photo is from a 1969-70 small block with an 8" balancer. This included, but was not limited to, ALL 1969-70 Corvette small blocks. This cover and tab cannot be used on earlier 8" balancer small blocks because the timing mark changed for 1969.

[Jim S.]

Re: Need photo of an original 65 L76 365hp timing tab

Timing Tab Paragon Number: 717 GM Part Number: Timing tab, w/327 w/Sp.Hi.Perf. Install on your timing cover. For use with 8" balancer. Years 1962 - 1965Type: Stock Additional Notes: w/327 w/Spec.Hi.Perf. Condition: New Packaging: Each Options: TIMING TAB || Price: $18.00

Here is what Paragon shows for 65 . It show the tab I have on the left as being correct for 66-67 , that makes me wrong, and seems to agree with Alan's picture .

Sorry for the misinformation if they are indeed correct. Again , someone here knows for sure .

[William G.]

Re: Need photo of an original 65 L76 365hp timing tab

Yes, my 65 L76 timing tab looks like the original in Alan's photo and the Paragon photo that Jim sent. Can I assume that each mark is 2* and the long mark five notches above zero is the 10* mark which is the base timing spec for the L76? Thanks to all who have responded. Bill Gould

[Jim S.]

Re: Need photo of an original 65 L76 365hp timing tab

The slightly arched tab seen on the left in the first photo is from a 1969-70 small block with an 8" balancer. This included, but was not limited to, ALL 1969-70 Corvette small blocks. This cover and tab cannot be used on earlier 8" balancer small blocks because the timing mark changed for 1969.[/QUOTE]

Joe,

Can't fool you ! That photo was one I already had stored from a question I posted a long time ago .It was identified as an early C-3 cover then . I only used it to demonstrate the two different sizes . No one ever said anything about the curve however .

Jim

[Alan D.]

Re: Need photo of an original 65 L76 365hp timing tab

Take a look at Help ID this timing Chain Cover

Good discussion on covers, a little more than what you asked. Think there is another one but have not found yet.

[Alan D.]

Re: Need photo of an original 65 L76 365hp timing tab

Well found some more information on these covers from Michael Hanson;

"Here's the story on the timing chain cover for 62 through 68. This issue with the timing chain cover and timing tab has been incorrect for decades.



For the new 8" damper for 1962, a new timing chain cover was required with a relocated timing tab to clear the larger diameter of the damper. The new 8" damper, part number 3817174 was used on all Corvette engines for 62.

Usage of this part/number continued through the 63 model year and likely into the early part of the 64 model.



That's when someone discovered that the timing tab was not correct. The original design tab from engines with a 6" damper was used on the cover for engines requiring an 8" damper. That means the distance between marks/lines on the timing tab were incorrect, (too close together) If you do the math, you find that the distance for one degree along the surface of the damper is larger for a larger diameter.




A new cover, part number 3851549 replaced the original 3817174, on paper, on January of 1964. I don't know when the actual change occurred in engine production though but suspect it was after the start of the 64 model year.


Also note the different method of attaching the new design tab to the cover.
On the 3817174 cover for 62-E64, the attaching tab is visible, facing up.
On the 3851549 cover for 64L-65, the tab is not visible, facing down. An easy item for judges to spot.


For the new 66 model, the part number of the cover assembly changed to 3885048 because a new design tab was required. For the first time, a timing setting that was retarded instead of advanced was used. I don't remember the actual setting but, supposedly, cars equipped with A.I.R systems required this new below zero timing setting. The new tab had a few more marks below the TDC line.


I don't know for sure but I believe the part number change to 3923290 for the new 68 model included a reinforcing rib between the mounting bolt holes. The C3 folks may be able to add info for this cover. "

[Larry P.]

Re: Need photo of an original 65 L76 365hp timing tab

Alan, thanks for the PN history. I'm working on a 1965 327 350HP L79 and assume the 3851549 cover would be appropriate for this application. Would anyone have a photo of the timing tab for this cover?

[Larry P.]

Re: Need photo of an original 65 L76 365hp timing tab

Alan, thanks for the PN history. I'm working on a 1965 327 350HP L79 and assume the 3851549 cover would be appropriate for this application. Would anyone have a photo of the timing tab for this cover?

Can anyone confirm this to be the correct tab?

[Don S.]

Re: Need photo of an original 65 L76 365hp timing tab

Just took this photo of mine. Believe it to be original cover on my 65 L-76.