Have any of you guys taken an aluminum driveshaft out of a late model car from the junk yard and had it modified to fit a 67-70 Mustang? I wonder if there are any out there that would work with a C4 that could just be shortened? I don't recall ever seeing a post on this topic, so forgive me if there is an obvious reason why it won't work.
I used anAerostar aluminum driveshaft when I did my T5 swap in my 66. I had it shortened about 4" to fit my setup and used the C4 yoke (cut down). I haven't had an oppurtunity to try it out yet though.
Aluminum driveshafts won't take much torque without damage. The u-joint yokes spread easily. They also begin to work harden as soon as you start to use them - definitely not a long term solution to anything. I will stick to steel from here on.
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Paul
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retired mechanic after 35 years
specialized in Holley carbs and Ford Automatic Transmissions
I have an aluminum in my car that sees strip time often. It is SFI certified, and has been inspected every year or so for recertification. 6 years later, no problems. We also run the same aluminum DS in our dirt late models, dont have any problems there either. Not to mention that there are several vehicles from the factory with alum shafts that have 100k miles on them, this includes trucks as well.
You definitely have to match the driveshaft to the application. I have a friend with at race car that twisted a 3 1/2" aluminum driveshaft. He went to a 4", and has not had anymore trouble. He is running between 850-900 hp. All aluminum driveshafts are not created equal. My car has around 400 hp, with a C4 transmission, I think a stock 3 1/2" should be OK.