Clarification regarding 69 Turbo 400 verients

[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...

[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

[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

[Mr70]

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