Any decent auto parts store should be able to help you with that.
Which one depends on what size on your drive shaft now and what size the yoke is.
Here's dimensions so you cam measure the cap size:
http://www.drivelineshop.com/specsheet.htm
It's usually a 1310 /1330 u-joint.

 

NAPA parts would be your best bet.
they have Precision brand u-joints.

What you most likely have is a 1310 series u-joint from the 10 bolt and the 12 bolt uses the larger 1330 series.

If the 10 bolt is a 8.5 the yoke in 99% of the time will interchange.
So you could just swap the rear end yokes.

 

http://www.summitracing.com/parts/PCN-253/

This should be the u-joint you need.

Al

 

Thanks guys. Looks like mine measure out for the 1310/1330.

I'll check Napa tomorrow and if no good, I'll order from Summit.


Bob

 

You may need to use a hybrid u-joint
to allow the little u-joint DS to mate
with the bigger u-joint pinion yoke.

Any good drivetrain shop is usually
a Dana/Spicer dealer, & can whip
this one up for you in a flash!

--------------------:beers:

 

For future reference in case anyone searches this thread, I found the U joint at NAPA. Part #PUJ353 (Precision) It was $20.29 + tax

This is the 1310/1303 U joint.

Got mine and I'm back to cruising! :hurray:

 

That's what I had to do to mine. And believe me that joint is plenty strong. I went 10.60's with my car with one of those conversion joints in it.

 

Hi guys, just so I understand this right.... Im about to put a 12 bolt out of a 67 into a 66 that currently has an 8.2 inch 10 bolt. I cant use the driveshaft(different transmissions-would need a different lenght shaft). So for now, I wanna continue to use the driveshaft out of the car with the 8.2 car. I am not yet sure what the fitment looks like but am I reading correct that one of these universals may be needed to allow me to retain the current driveshaft that was mated to an 8.2 rear, but bolt it up to the 12 bolt with the larger yoke? Thanks!

 

Yes, a conversion joint is needed.
The 12 bolt should be a 1330 series and the drive shaft a 1310 series
Precision u-joint makes a #253 conversion joint available at NAPA and O'Reilly part stores.


Al

 

Does this also apply to a 1968 Chevelle going from a 10 bolt 8.2 to a 68-72 chevy 12 bolt?

 

yes, it should

Al

 

Not all 12 bolts were 1330's; usually originally produced only behind a big block ,th 400 car.
1310 are 3 1/4" wide ;1330s are 3 5/8 wide.5-134 is Spicer crossover u-joint