1965
L78
1966
L78
1967
L78
1968
L78
1969
L78
1970
L78Frequently Asked Questions
Q: How many L78 convertibles were built?
A: There
is no known breakdown of L78 optioned
Chevelles by body style or how many came with optional gear ratios,
specific transmissions, radios, etc. and will probably never be known
unless I can register and document all L78 cars sold, which isn't in
the realm of possibility for obvious reasons.
See How Many L78s Based On Body Style Were Sold? for more insight on L78 numbers vs. body styles.
Q: Didn't all L78 cars have gauges and a tachometer?
A: No. The Instrument Panel Gauges, or Special Instrumentation, sold
under RPO U14 was always an option regardless of year for L78s.
Q: Is my L78 real?
A: This can be tricky at best.
To some, 'real' means the car has the correct and original engine it
was born with and can be matched to some form of documentation. To some,
it means if the documentation says it was born with the L78 option,
it doesn't (relatively) matter that the engine has been replaced for
one reason or another; whether by a dealer under warranty or an over-avid
enthusiast 'back-in-the-day' due to out of warranty breakage. Consider
if the car has a warranty engine with CE code or a base 396/350 motor
dressed to appear as a L78 engine, but has documentation that is original
to the car as noted by the VIN sequence and other information of the
sheet matching the trim tag.
As far as the L78 Registry is concerned, correct and valid documentation is the primary objective in the registry, not current engine.
Q: Wasn't there an L89 engine as well?
A:
No. There was an L89 aluminum head option available on the L78
engine, no L89 aluminum
head options was offered.
** 1966 Chevelle: A total of 3,099 L78
Chevelles were sold in 1966. These were limited to the SS396 series
and 13480/13680 El Camino, no L89 aluminum
head options was offered.
** 1967 Chevelle: Only 612 L78
Chevelles were sold in 1967. Initially dropped for the lineup the
L78 began appearing quietly around March of 1967. These were limited
to the SS396 series and 13480/13680 El Camino, no L89 aluminum
head options was offered.
**
1968 Chevelle: A total of 4,751 L78 Chevelles were sold in 1968.
These were limited to the SS396 series, no L89 aluminum
head options was offered.
** 1969 Chevelle: Of the
9,486 L78 Chevelles sold in 1969, 400 were additionally optioned
with the L89 aluminum head option.
** 1970 Chevelle: Of the 2,144 L78
Chevelles sold in 1970, 18 were additionally optioned with the L89
aluminum head option.
** 1968 Nova: Only 667 L78 Novas were
sold in 1968 due to their late introduction. No L89 aluminum head
options were sold.
** 1969 Nova: Only 5,262
L78 Novas sold in 1969. No L89 aluminum head options was offered.
** 1970 Nova:
Only 3,765 L78 Novas
were sold in 1970. No L89 aluminum
head options was offered.
** 1968 Camaro: Of the
4,575 L78 Camaros sold in 1968, 272 were additionally optioned with
the L89 aluminum head option.
** 1969 Camaro: Of the
4,888 L78 Camaros sold in 1969, 311 were additionally optioned with
the L89 aluminum head option.
** 1970 Camaro: Only 600 L78
Camaros were sold in 1970, no L89 aluminum
head options was offered.
It is not known how many of any year or
Chevelle/Camaro L78/L89 are broken down by manual or TH400 automatic
transmissions nor how many of any particular engine went into any
one particular body style.
Q: When did the L78 become available?
A:
According to an GM internal engineering memo dated in December of 1965
the L78 was axed prior to the beginning of production of the 1966 model
year, but was "reinstated" in late August of 1965. There was
no advertisement of the availability of the L78 to dealers until February
1966, and no public advertising until later than that. And the option
was never added to the Chevelle/El Camino order form at any time during
the model year. It had to be penned in in a blank line beneath the pre-printed
list of available engine options.
The production of the L78 officially
ceased being available, or more accurately "...in the process of
being cancelled..." in a GM letter dated October of 1969 that coincided
with the introduction of the LS6 engine option for the 1970 model year.
The last known (at this time) dates for an L78 optioned Chevelle from
Atlanta has a scheduled date of November 12, for Baltimore it's November
25, for Van Nuys it's October 11. I have no build sheet data for Arlington,
Flint, or Kansas City to verify those three plants. For more information
on the LS6 engine option, see the LS6 Registry at
http://ls6registry.com.
