1971 & Newer Unidentified Timing Chain Cover for 8" Harmonic Balancer

[David L.]

Attached are 2 photos of a timing chain cover for an 8" balancer that I always believed was used on Chevrolet Trucks in the 1970's. I bought it at a swap meet decades ago. The tab has a single spot weld as well as brazing on each side of the tab which I think was a repair. The single spot weld also appears on the back side. It has been brought to my attention by someone who owns a 1973 Corvette with original L82 engine and a cover similar to this one with a welded on tab.
I have always thought that 1971 or maybe 1973 and newer engines came with a timing covers that required a bolt on tab.
QUESTION: Was this cover ever original equipment on Corvettes in the 1970's?
Dave

[Tom R.]

Re: 1971 & Newer Unidentified Timing Chain Cover for 8" Harmonic Balancer

David
According to the 3rd Edition of the 73/74 manual, the tab for L48/L82 was spot-welded to the timing chain cover in 1973. Initially in 74, tabs were spot-welded but mid-production bolts were used. In 75-77, tabs were spot-welded in three points. Perhaps the St Louis factory ran out of the spot-welded covers in 74 and borrowed from the truck line? The photo is a 74 L82 and shows three spot welds.

We must remember that as production increased in the 1970s, we see what is described in the AIMs, ROLLING PRODUCTION CHANGES, which suggests restorers should not expect absolutes. What revision teams have found in 73/74 and 75-77 TIMJGS, is that anomalies are common.

TimingTabL82_74.jpg

[David L.]

Re: 1971 & Newer Unidentified Timing Chain Cover for 8" Harmonic Balancer

Tom,
Thanks for the info. I have seen these covers with this style of welded on tab in Chevrolet Trucks in searching for parts in the salvage yards in the 1970's and 1980's. It seems that every day I learn something new. The cover shown in my post has the number "22" stamped on it in the center which I assume means the 22nd week of the year. I have collected various other timing cover with more compete dates. Example: "33" and "69" (33rd week of 1969) on a 1969-1970 Z28 cover for 8" balancer. As I remember the date codes started in 1967 with some complete and some incomplete.
Dave