My 6 year quest for a CX coded THM400 just ended

[Mr70]

Nice find,and good looking Original CX tag as well.
I wouldn't balk fo a minute on that engine timeline,it all seems acceptable.
Even that Trans. falls into perspective.
C=Chevrolet
X=Solid Lifter engine applications
69=Model year
2160=Serial No. My records show this falls into the right time line.
395=Assembly day starting with January 1st,1968 which decodes as Friday January 30th,1969.

Just curious..Have you thought about hunting for the Nova itself these came out of?

[nuch_ss396]

[ QUOTE ]
Nice find,and good looking Original CX tag as well.
I wouldn't balk fo a minute on that engine timeline,it all seems acceptable.
Even that Trans. falls into perspective.
C=Chevrolet
X=Solid Lifter engine applications
69=Model year
2160=Serial No. My records show this falls into the right time line.
395=Assembly day starting with January 1st,1968 which decodes as Friday January 30th,1969.

Just curious..Have you thought about hunting for the Nova itself these came out of?

[/ QUOTE ]

Rick,

The seller told me that the car was chopped up for racing
many years ago. No idea of where to find it. You know
how these stories usually end.

One question though. Can you tell me exactly what the
2160=Serial No. pertains to? How did you determine the
time line based on the number?

Steve

[Mr70]

Chevrolet kept track of some of their Transmissions for service reasons through their serial numbers.
Yours was built at the Cleveland Plant.
They produced a spiral bound catalog.
I own that catalog.

[Jeff H]

Steve, figure that most people didn't know that you could order the L78 with an automatic in 69 so the engine could have been assembled way before it was ever ordered for a car. It also could have been a motor that was built and failed inspection due to some component being bad so it sat around before being fixed and placed back in the "rotation".

[Rick H]

[ QUOTE ]
395=Assembly day starting with January 1st,1968 which decodes as Friday January 30th,1969.

[/ QUOTE ]

1968 was a leap year (366 days) so the assembly date should be Wednesday, January 29th, 1969 unless they stuck to the 365 days in a year as the standard rule. The 30th was a Thursday as well not Friday.

Rick H.

[Mr70]

You're right,I was looking at my January 1970 calender.

[nuch_ss396]

I want to thank everyone for the verification you've given
me on the L/78 & CX THM400.

OK, now that it appears that I have a true JL coded L/78,
my attention turns to rebuilding the CX THM400. It has
been sitting for almost 30 years and I want to have a good,
qualified shop rebuild it. I would be looking for a shop
that understands what the CX is and how to build it as it
came stock. Also, I will need the 6 mount point converter
for the CX. Are they still available from GM?

Can anyone recommend a good person or shop to rebuild the
CX THM400? As they say, you only get one chance.......

Steve

[John Brown]

Tranny rebuilding isnt brain surgery. The main problem doing it yourself is the clutch pack compressing tools. If you can rebuild an engine, you can do an automatic. Turbo 400's arent so complicated that with a good manual you cant do it yourself. I was always afraid of automatics but I couldnt run on the NHRA record with my stick car so I changed to a glide and ran about 3/10's under.

Built my first trans on the ramp of my race car trailer. When that one worked I wasn't skeered any more.
Give it a try !

[Mark_C]

Engine couldn't have sat around waiting for repair, it wasn't assembled until February something of 69 by the assembly code on the pad and most of the other components bolted to it are dated in early 69. The block was cast way back in mid 68, and it could have sat around somewhere at the foundry before it was assembled in the engine plant. But once the machining and assembly process started the engine was built and shipped off to the vehicle assembly plant.

The assembly plant (the car one, not the engine one) had some limited storage capacity for batch built components, like HP engines, but not alot.