I've been investigating a vibration issue. Its speed dependent and not rpm dependent so today I took off the driveshaft to inspect it and I'll probably go ahead and at least get some new u-joints pressed on. When I pulled the driveshaft off I noticed a shiny area that looked like it was rubbing on something. Here's a picture.

http://i183.photobucket.com/albums/x168/Autoengineer/IMG_0814.jpg

I looked back under the car with a light and it turns out the emergency brake cable has been sitting on top of the driveshaft. There's a wear spot on the cable also where you can see where it was touching the driveshaft. I don't know if that was causing the vibration, but it can't be a good thing. Should the e-brake cable run under, over, or anywhere near the driveshaft?

Can't say it's correct, but mine rune under the driveshaft.

I've always seen them run under. If the trans has been changed from a th-400 to a th350 or vice-versus then the cable were probably not chnged to the correct ones.

Should run under. My exhaust keeps it off the driveshaft.

It seems like the driveshaft sits too high in the floor pan hump for me to run it over the top of it. I'll have to play around with it to see if I can run it across closer to where it connects to the tranny. Also, I inspected the driveshaft and there's no dents and the original weights appear to be intact. Should I consider getting it balanced anyways?

Yes of course have it checked out. As a note, I ran into a similar situation a few years back. Turned out the drive line was slightly twisted. I layed it on the ground and one u-joint was just a few degrees out of alignment from the other. So if you need to build a new one you may as well have a stronger one built. I did a 3 inch with .083 wall thickness and 1350 u-joints. Not cheap though.

(Homer Simpson voice) Mmmmmm...1350 U-joints...

I had a friend with a '68 Chrysler Newport back in high school. That 383-2V threw so much torque (and was driven so hard) that he wound up the driveshaft like taffy. I think he got one from the salvage yard from a 440-powered car; it was larger diameter and never gave any problems.