ZL1 Production Numbers?

[TonyHuntimerRaceHome]

Before you point me to the page that everyone has read:
http://www.camaros.org/geninfo.shtml#COPO

Why do the ZL1 production numbers (90) and crate engines (17) have a tilde (~) in front of each (~90) and (~17)?  That seems odd.  Does this mean that these numbers have been questioned in the past and that at least one historian "in the know" remembers a different number?  It not only seems odd that Chevrolet didn't produce more that ended up in R&D and other racing programs.  Wait!  What am I saying?  Chevrolet wasn't racing.

In Paul Van Valkenburgh's book,"Chevrolet ---Racing?" he refers to aluminum big block 427's in racing.  He states, "Penske immediately picked up a half-dozen which were shipped to Traco, McLaren bought a bunch, and the 1968 Can-Am season was off to become a relatively competitive series." He also states, "The production aluminum-block 427 Chevrolet engine saw finally made available to the general public. Most were sold across the counter at around $2000 for the short block, but some were built in Corvettes and Camaros."

Is the ZL1 that we say only (~90) were produced, is that only complete engines? I take that as meaning there were A LOT more of these blocks produced, but only (~90) were complete engines. Any insight? 

Thanks,
Tony Huntimer

[tom]

2 ZL1 Corvettes
69 ZL1 Camaros
~ would seem to me, the same as around, might not be exact.
Others will chime in

[69 Z11]

Most people don't have the ASCII code handy for the double tilde, ≈, which in mathematics, reads as "approximately equal to".  So they use the single, ~, which is available on standard keyboards.  In most cases, the single indicates an approximation and can be read the same way as the double.