U Joints

[miknjan]

okay heres my dilema. I just install a 78 Trans AM with 4 link rear end in my 54. Now come the hard part. the yoke on my new rear end is a different size now the driveshaft wont be correct. I believe iv'e heard that you can buy u joints with different sizes of caps and lengths. Anybody have a clue as to how to figure out what i need?

[mr48chev]

Spicer and Neapco among others has a line of conversion joints. I have one in my driveline between the yoke and shaft because they are mismatched.
Somewhere online there is a chart but I'll have to do some searching or you can check at your local parts house.

What you need to do is figure out what universal joint each side needs As what is in the driveshaft now and what fits the rear end and go from there. I can tell you from experience that they aren't cheap compared to a standard u-joint.

Click on the U joint catalog and when it opens in pfd scroll down to the conversion joint page and click on it.
http://www.neapco.com/n_products-catalogs.php

Once you get the correct u joint number for your application you can use that number to have your parts guy find a u-joint for you although it has been suggested by several guys who work with driveshafts on a regular basis that the Neapco or Spicer brands have a better quality as a norm.

[entourageguy]

If you go into a good auto parts store where the people will look up the info tell them what the rear end is and the drive shaft. They will be able to look up the correct u-joint.

[gmcer]

I just did the same thing. Go to a good parts store with both joints and no problem!