[lonestarcamaro]

Hi can anyone help please, a '67 Camaro that had been setup with a BB 454, TH 400 Trans and 10 Bolt Diff, since replaced the TH 400 with a Muncie 4 speed M 20 put in the original gearbox cross-member and got rid of the aftermarket for the TH 400, now the drive-shaft is quite a-lot shorter and will not mate up, it's appears to be a few inches short, are there two different length's in driveshafts?

[bcm66]

The TH400 driveshaft is different than that used with a big block and Muncie. This is because the TH400 transmission is a little longer...

How long is the driveshaft you have? Measure from the center of one u joint to the center other u joint. The 67 and 68 big block with Muncie driveshaft should measure about 50.46 inches. This is from the AMA specs.

[lonestarcamaro]

Hi my friend thanks for the help, just measured the shaft at 47 inches so looks like I need to find another shaft, are there just the two shaft lengths available!

[bcm66]

The stock driveshaft for 67-68 Camaros with small block and L6 engines is 49.96 inches long. Most 69 Camaros used a 49.56 inch long driveshaft.

Do you have a stock 10 bolt rearend in the car or a later 8.5 Nova 10 bolt?

You might need a custom driveshaft.

Here is how you need to measure. Insert yoke of driveshaft all the way into the back of the transmission. Then pull that out about 1 inch. Then check to see how much longer the driveshaft needs to be to match up with the yoke on the rear axle. You might need someone to help you do this.

[Vega$69]

Originally Posted by bcm66

The stock driveshaft for 67-68 Camaros with small block and L6 engines is 49.96 inches long. Most 69 Camaros used a 49.56 inch long driveshaft.

Do you have a stock 10 bolt rearend in the car or a later 8.5 Nova 10 bolt?

You might need a custom driveshaft.

Here is how you need to measure. Insert yoke of driveshaft all the way into the back of the transmission. Then pull that out about 1/2 inch. Then check to see how much longer the driveshaft needs to be to match up with the yoke on the rear axle. You might need someone to help you do this.

The shop I use for drive shafts says yoke in pull back 1" and measure. Also do it with the car sitting on all four not with the suspension hanging.

[bcm66]

Yes, 1 inch is probably better. I went back and changed what I posted. I didn't type what I was thinking.

You need about 1/2 inch of travel and that extra 1/2 inch for "security".

[lonestarcamaro]

Hi thanks for the helpI measured my 68 RS driveshaft 10 bolt diff, 2 stage PG today its close to 49.7 inches so tried it in the other Camaro bolted straight up but sits out a bit more on the muncie than the powerglide, hard to say how much really goes into the trans but would be a good 1 3/4" to 2" should this be enough, considering that there is no weight in the back of the car as yet, dosen't have interior, gas tank etc so I figure that once the extra weight goes into the car this shound pull down the rear suspension abit thus sliding shaft further into the trans, what do you think?

[bcm66]

Francis, post a picture of what it looks like with that 49.7 inch long shaft installed.

I like to see as much yoke as possible into the back of the transmission (but with that 1 inch of gap between the end of the transmission and the big end of the yoke).

I don't have an exact yoke like what you have, but just measured a TH400 yoke in the garage and it is 4 inches. So if they are similar that means you would only have half of the yoke inside the transmission.

Unless it is done correctly, you may end up with vibration issues and/or problems with the bearing and seal at the back of the transmission. So I think it will be important to get things right the first time before you get the car on the road with that new setup.