Clarification regarding 69 Turbo 400 verients

[nuch_ss396]

I have a fast question for the members that I'm sure can be
answered rather easily. I'm in the process of restoring a
L/78 69 Camaro that had a THM400 originally. It is long
gone and I need a correct replacement. http://www.yenko.net/ubbthreads/images/graemlins/confused.gif
Here are the questions:

1) What were the codes for the THM400's used during the 69
model year? CC (396-325), CE (396-350), CY (396-375),
CX (427-425 & ZL-1)? Are the codes listed correct?

2) Which THM400's used the 6 mount-point converter?

3) Does anyone have the correct THM400 & converter for my
restoration project available for sale?

4) If the correct coded THM400 cannot be found, any
recommendations on where to get a standard THM400 rebuilt
to correct original CY or CX specifications including the
correct 6-bolt converter? I would also need a correct
THM400 ID tag stamped accordingly. http://www.yenko.net/ubbthreads/images/graemlins/dunno.gif

I would like to know what other members here have done in
this regard. There were only but so many of these correct
coded THM400's around.

Steve

[Belair62]

http://www.yenko.net/ubbthreads/showflat.php/Cat/0/Number/109754/an/0/page/0#109754

[fpcopo]

Lots of differences. You need the high shift point governor, impossible to find. You can trim some off your governor weights or use V12 Jag governor to raise your shift points. I think the CX was set to shift at 5,800 to 6,100rpm at WOT in Drive. Line pressure being raised will increase shift point with no other mods. Its a balance between governor weights, rpm and line pressure. Direct drum has 2 bleed off ball checks instead of 1 to speed dumping of oil and shift speed. A good machinist can easily add a ball check hole to a regular drum, you can also machine your drum plate to accept 1 more clutch plate. I think the L88 convertor is still available? Accumulator springs and valve body differences are numerous but a shift kit will take care of most of this. The link to the thread Bob posted has a lot of the differences. all the parts were listed in the sheets I sent to Ray Morrison. I have the CX and CY tags available for $29+ postage. Frank.

[nuch_ss396]

Hi Frank,

Thanks for the information! http://www.yenko.net/ubbthreads/images/graemlins/biggthumpup.gif

Now, based on the information you posted here, it appears
that I may be able to have a "sort-of" CX THM400 built.
Big question is who can do this and what kind of $$ am I
looking at to accomplish this? Do you have any
recommendations regarding a shop that can assist me in this
endeavor?

I will take you up on that ID tags shortly. How should I
get in contact with you?

Thanks again,
Steve

[fpcopo]

Steve, you can email me at the address in my profile or call at 402 393 5252. You can make a trans that works just like a CX. It won't be super expensive but finding the convertor, big block valve body casting and the Jag governor will take a little time. Frank

[Mr70]

Frank repop the CW tag for cryin out loud!
I'll buy ya a Saasage wit. http://www.yenko.net/ubbthreads/images/graemlins/grin.gif

[fpcopo]

Da saasage sounds good but the problem is I had a bunch of these tags made and I'm gonna die with em. The only 70 tags I've got are CYs.

[Chevy454]

Steve: what are your intentions with your car? If it's NOT gonna be a regular at the strip, I'd just get a THM400 from a reputable tranny shop and be done with it...it will last forever, and if you're wanting the look of the 6-bolt converter then buy one (don't they repo these?) and bolt it on. If you want to get really involved, B&M sells a governor weight kit that explains how to taylor the trannys shift points to your needs, but I wouldn't mess with it...

[nuch_ss396]

Certainly, any THM400 would be cheaper. I was just hoping
to find an original CX THM400 for the originality factor.

Steve http://www.yenko.net/ubbthreads/images/graemlins/ooo.gif

[nuch_ss396]

Can anyone verify for me if the front pump cover on the CX
or CY THM400's had eight bolts vs. six bolts on the standard
pump cover. I have two THM400's in my garage and one has
6 bolts and the other has 8 bolts. I have been told that
the CX and CY THM400's used 8 bolts and that is one way to
know it's a CX or CY. Did any other THM400's use the 8 bolt
pattern?

Any input?
Steve

[Chevy454]

Look at the chart in the link Belair posted above...if there are any dissimilar parts used between a CY/CX trans and a normal trans, that chart would show it.It also shows the part #s, so pull scribble down the part number and take a look at the chart...if you can't find the number on the chart, holler back, and I'll pull out the original Hydra-matic papers and take a look...

[Mr70]

I can't remember exactly,but I think my CW TH400 (L78) uses 8 bolts.

[nuch_ss396]

I just reviewed the chart. I'm not sure if the "cover
assembly conv. housing" on the chart refers to the pump
cover I was referencing. Any chance you can find out?

Steve http://www.yenko.net/ubbthreads/images/graemlins/confused.gif

[copo-2]

nuch ss396,

The CY code redesigned Turbo-400 came out in the 68 COPO Novas that were built for Fred Gibb. It was the first of the automatics to be put behind a high horsepower, solid lifter engine, in which the purpose was to get Chevrolet involved in the automatic classes of NHRA drag racing. This run of Novas was built the first 2 weeks of July, which was near the end of the 68 run. Thus, these redesigned transmissions were actually referred to as 69 experimental automatics. The CX code Turbo would replace the CY on October 25, 1968, meaning most, if not all, of the 69 high performance solid lifter cars would have the CX code? The CY transmissions had an 8 bolt flange holding the front pump, which undoubtly would hold true for the CX,as well? One of the main differences between these two transmissions, I think you will find the CX transmission used a little higher stall converter. Ray

[nuch_ss396]

Thanks Ray.

Can you tell me if only the high HP versions of the THM400
used this 8-bolt pump cover? I have two THM400's here and
one has a 6-bolt cover and the other has an 8-bolt cover.

Steve