Hey there Mr. P - I am agreeing with you - .040" is way out - the point of my post is you would think a "shop" doing this kind of work would follow some basic guidelines for runout. Was wondering if they ever made it right? Just wondering.

I took it back but they said I MUST have done something
to it to be out like that.. I told them I pulled it out
and turned it 180 then tried it again... was still bad
but they didnt want to give my money back..it had a total
of 3 passes on it

So, which shop is this that sells nonrefundable banana-shaped shafts?

Mr P if interested in salvaging the shaft call a local marina service shop and ask where they take shafts that need straightening. Boat prop shafts are always getting bent.

I forget which shop it was and I dont want to bad
mouth the wrong shop but it was one of the more well
known places.. this was about 20 years ago when I
built my Valiant

I took off all the parts and trashed the tube.. but I
know what your saying about the marinas getting solid
shafts straightened .. I had my old boats shaft done

Got any driveline company's in your city?

We have several and I deal with a couple of them since I own a fleet of trucks. I had one built for BB E body over 10 years ago. It runs smooth to over 100 MPH and was very reasonable in cost.

This is coming from someone who has bought a ton of Mark Williams products over the years. IMO shipping is too high for something common like a drive shaft that can be made local for a door car. Yes even for a "race" car.

Yup I weighed it and it weighed less than my steel driveshaft.

I went from a 8.75 rear to a dana rear and needed it an inch longer I think? Took my old shaft down there to the local driveline shop and said I want it an inch longer and they got it right the first time. I know them also so why not support the local guy?

i always support the local guy when possible. but with that said, make sure your local shop can balance the shaft at more than 1000rpm. the truck places around here only have low rpm balance. when you combine deep gears and overdrive, your drive shaft is turning considerable rpm at 70+ highway speed, and even more at the track without overdrive in the picture. a truck shop probably isn't the place to consider obtaining a shaft from. i've run into this too many times to not think in this manner.

I don't buy this, my trucks have 6:13 and 5:38 gears in them...The truck driveline shops can balance your driveshaft. They do all driveline work, not just trucks.

Yes they have steep gears but also have BIG tires
for the loads... they dont turn that many rpms and
it seems that trucks shops dont care if there is a
bit of vibration since they have a lot of vibrations

I noticed that some places like PST will SFI certify a shaft. When is this necessary? Is there a know amount of weight savings from a stock driveshaft to a C/M shaft to an aluminum shaft? normal length, approx. 52". Mine was built so long ago, I don't even know what material it was built from. Local shop where I worked did it. Just trying to decide if an upgrade is worth it. Aluminum doesn't seem to be able to handle to power levels of C/M. I need to weigh mine, later, for comparison to anyone else.

CM is much stronger than 6061.
AL weight savings is only a tiny bit more than the actual difference (in lbs.) even though it's rotating weight, because the mass center of rotation is so small.

Remember: O/D doesn't slow down the driveshaft speed, only the engine speed, the shaft still runs at the rear axle ratio.

Action Machine, best for the money.

Who was the company who built the bad shaft Mike? Was it Cameron's Cove?

My u joint center to center is 42 1/2". Fitted with 1350 joints and a Mark Williams slip yoke. It weighs 21 pounds. Can anyone tell by the weight if this is just old school steel or thinwall C/M? Do I need to upgrade my driveshaft for an 8 second car?

As I said before.. I dont recall.. too many years
now... but it was not the one you named

I'm getting ready to order a driveshaft for my 68 cuda. Being that i'm starting from scratch, what would you guys get, Aluminum or steel? 950 hp 850 tq. street car with a 4 speed. maybe around 3300 lbs. I would like the aluminum for weight savings, if it would be strong enough...

Myself I would go with steel on the street.. I
called Dynotech to see what I should go with..
they said DOM so I did with good U-joints and
yokes

Why aluminum?
Anyone do back to back test?

Pretty pricey back to back test