Drive Shaft length

[bwlizard]

I am switching from a 4 speed to a 727 auto in my 74 Duster. Does anyone know if the drive shaft length will be the same ?

[dirty dan]

don`t worry be happy .Mother mopar is generaly consistent in her disitions. I Gone from auto to 4 speed in both Band E bodies befor and used the same drive shaft from the 727 perfect fit . I would Imadgine mother would also look out for us on the A bodies as well. Iam just now changing the pedals in my 73 dart. It`s growing to be a 383 4speed. as soon as I get over the going pain it will be a fun cruzzzzzeeerrrr. Dirty Dan

[Ausydad]

I keep hearing of guys going from 4 spd to auto. My only question is how come I can't seem to find one that will sell or trade his flywheel, pedal cluster, and Z bar to me???? I'm still trying to get the pieces to do this swap in reverse. BTW, the shaft should be the same and Good Luck!

[bwlizard]

Ausydad, I would gladly sell you my flywheel and z bar. I don't think that I am going to mess with the pedals right now.

[bwlizard]

Well I found out the truth. In 1974 at least the drive shaft for the 4 speed is 4 inches longer than the drive shaft for the 727 auto. So I took it in to be shortened and they found that it was a double tube they said that they could not shorten it and that I would need to buy a new one for $215 ouch!

[Ausydad]

Sorry to hear about your luck. Email me about the bar and wheel to help defer the cost
Ausydad@yahoo.com

[72Challenger]

Is there a gap at the end of the driveshaft where the smaller tube goes inside the larger one? If so, you don't want to use that shaft for performance use anyway, it won't hold up.

If you can't see the inside tube, and the shop only found it when they cut off the yoke, then it's an Internal Vibration Absorber (IVA) driveshaft. According to my sources, these were no longer made by 1974. Could have been swapped in sometime before you got the car, however.

If it is an IVA then sorry to hear you got ripped off by an incompetent shop. You should try to get them to replace it for you. Those shafts can be shortened, if you cut off the rear yoke. The inner tube doesn't run the full length. Anyone who knows Mopars knows you ruin the shaft if you cut off the front yoke of an IVA shaft, and since you can't tell by looking, always cut from the rear. If this is the case, they owe you.

[72Challenger]

By the way, if you do need to have a new shaft made, make sure you get the yokes for the 7290 style universal joint. With a 4-speed, you should already have them, but from the sounds of the shop you're using, better double-check.

[bwlizard]

72 Challenger, Thanks for the info, I will bring this up to the shop and see if they will compensate me.