Number of 68 COPO Chevy II s ??

[Mr70]

Wasn't the M40 & the TH400 one in the same?

[brideinabq]

No, there was the M40 first

[brideinabq]

The M40 was a high performance tranie

[Kurt S]

[ QUOTE ]
Wasn't the M40 & the TH400 one in the same?

[/ QUOTE ]

Yes. M40 was the ordering code for a TH400 trans. Same code used for all TH400's.

In 69 (not sure on other years), M40 was also the ordering code used for the TH350's and showed up on the window sticker. M38 was actually the internal GM trans code for TH350's. Go figure....

[brideinabq]

The M40 used in the 68 COPO NOVA was a very different tranie it had a 6800 rpm shift point 6 bolt pattern and one extra disc .There were only 52 of the very first ones , the other 2 were used in the Camroe paces cars used a the Indy 500 that year.

[copo-2]

[ QUOTE ]
The M40 used in the 68 COPO NOVA was a very different tranie it had a 6800 rpm shift point 6 bolt pattern and one extra disc .There were only 52 of the very first ones , the other 2 were used in the Camroe paces cars used a the Indy 500 that year.

[/ QUOTE ]

Since the 50 Gibb Novas were built the first 2 weeks of July 1968 and the Turbo 400 was redesigned for the high horsepower, solid lifter engine for the COPO # 9738 order, I am interested in finding out about the 2 transmissions built for the Indy 500 Pace Cars? James, are you speaking of the 69 Pace cars that you mention of having the other 2 experimental Turbo-400's? While there is another designated COPO number in some material I have seen for the 68 models, I have never been able to find anything on this? The engine code is basically the same as the Gibb cars, but listed as COPO #9626, I believe?

To be specific, the new experimental automatics that was redesigned for the Gibb cars had the capability of 7800 rpm. Actually, these transmission were much like the original 400's in as much as they would shift much like the first Turbo's, but could be manually shifted at points over 7000. Shift points in Drive were less as they had a vacumn modulator valve like any other. Several different codes for the 400 was used by Chevrolet, in fact there were 16 different codes for different applications used in Chevrolets in 69. Though the Gibb cars were built in 68 and the experimental Turbo-400's were also built in 68 for the Gibb Novas, these transmissions were called experimental 69's. Remember these Novas were built right at the 68 models end.

[mr396]

I think the reason the M40 was so rare in 1967 and 1968 camaro and nova is it was a rather costly item at $368.How much did the M40 cost for the L78 68 nova?I rember in the 70's Art Carr in fountain valley ca built the TH400 in my 1970 Corvette and he told me I could leave it in first gear and it would shift into second gear.When I went to Orange County raceway and tried it,it took me a couple of runs to get the nerve up,but i'll be darn if it didn't shift.does all M40's do that?

[Kurt S]

M40/TH400 Camaro totals
67 $226 1,453
68 $237 5,466
69 price was $222 for the L34/5, $290 for the L78.

The 68 solid lifter version was the precursor to the regular production 69 solid lifter version.
But doubtful the 69 pacers would use a 6 month old 68 trans when it was already available and in production at that point. And they didn't plan that far ahead on the drivetrains for a pacecar that didn't exist yet.

[Kim_Howie]

Before the trans in the Gibb they had to manually shifted , you had to lift and then they would shift. The Gibbs trans would automatically shift with out having to lift,

[Keith Tedford]

Back in '68 a friend had an SS396 L35 turbo 400 Chevelle. Left in low gear, the transmission would shift pretty hard on it's own at 5200. It felt like there was a shift kit in the trans. In drive it shifted normally. At one point this car would hardly turn a tire but was getting terrific gas mileage. In checking, I found that the power valve piston controlling the primary metering rods in the Q'jet was stuck in the down position. I tore the carb down, freed up the power piston and the power came back but the gas mileage went back down to normal.