Quote:
Originally Posted by lycan
If i understand you correctly, internal GM documents show that:
- Only two (2) 1969 Corvettes were built with "RPO ZL1" option code, correct?
- The two (2) cars must have been built between 12/9/68 and September 69, correct?
|
On point #1 above: From two reports that showed 1969 model year production, both had 2 RPO ZL1 listed. If I recall, one report was through September 1969, and then the second report showed all of 1969 including the extended 1969 model year. Both reports showed only 2 RPO ZL1. These documents were sourced from magazine articles and previously published lists and were not found in the GM Heritage Center with the other trove of ZL1 related documents.
On point #2 above: That is what the internal GM documents from GM Heritage Center seem to indicate.
However, I think the second point is likely stronger: the internal GM documents indicated that "12-9-68" was the first "parts availability" date for an RPO ZL1 engine available at St. Louis plant for installation into a production Corvette. From what I understand, GM did not leave rare engines sitting around to be installed sometime well into the future, thus these documents seem to indicate the first RPO ZL1 was built on or slightly after 12/9/1968 given documentation shows that the Daytona Yellow ZL1 was definitely a RPO ZL1 and it was built in September 1969.
An additional important discovery in internal GM documents found at GM Heritage Center was that the type L88-engines were actually built with closed-chamber, despite the original CEC engineering plan for them to be open chamber (which was what appeared in various magazines in period). However, a "Stop Order" was placed on the open-chamber L88/ZL1 engine due to problems with the aluminum cylinder heads, which extended the closed-chamber models (including IT L88) for the 1969 model year way beyond the original engineering timeline. I don't have the data in front of me, but I believe this stop order was lifted sometime in the March 1969 timeframe, likely coinciding with the Camaro ZL1 engines released for "production" COPO 9050 Camaros starting with chassis #3. The first two "red hot" COPO Camaro ZL1s were requested by Pete Estes to ship out by December 31, 1968, for homologation/racing purposes and were not "customer" cars. As this was a production engine reliability issue for the ZL1, the lifting an engine stop order would probably have applied to Corvettes and Camaros at roughly the same time.