The CV joint knuckle in the front driveshaft is.

I'm surprised the guys at the salvage yards couldn't help. Did you see them use a "Hollander" Guide to look up your part? That is huge, really expensive book that lists all the parts with a code number, then under that number it tells which vehicles use that part.

My next suggestion is to remove the old shaft and march down to one of the pick-your-own-parts yards and match it up. Or you can measure the lengths fully collapsed and fully extended. If you're anywhere between Ohio and southern Georgia, there's real nice chain of yards called "Pull-A-Part" where you pay your buck, throw your tool box in one of their wheel barrows, and you can spend all day there. Parts are very inexpensive, the employees and customers are very friendly, and the yards are very clean and well-organized. I've been to 16 of their 23 yards and have gotten a lot of good deals. You can do an internet search to check their inventory but it won't tell you colors, options, or which parts have already been removed. Some of the yards have cars as old as 1960 models. A few have a few rows of even older cars and trucks. They don't buy insurance wrecks. They only have what owners bring in so a 2000 model is about the newest you'll find.

I never looked into buying them because they are so expensive and would get used so little. However, I just did a search on eBay and found one for 1975 - 1990 cars and trucks for $36.00 or best offer. These books typically go for hundreds of dollars at live auctions. Do a search for "Hollander Interchange".