[letsroll]

Got my 8 inch out and started comparing a few things and much to my surprise the u-bolts from the 8 yoke are larger is spread that what is in my 9 inch N case! It appears the 9 takes a smaller diameter cap joint. This seems extremely backwards to me??!?!!?

 

[posidude]

Here is a chart to ponder.

Outside Snap Ring U-Joint / End Yoke Chart​

For Dimension E using the end yoke, measure inside the two Dim. D
Dim. E
Series
1 1/16"
3 7/32"
1310
1 1/8"
3 7/32"
1310 Special*
1 1/16"
3 5/8"
1330
1 1/8"
3 5/8"
1330 Special*
1 3/16"
3 5/8"
1350
1 3/16"
4 3/16"
1410
1 3/8"
4 3/16"
1480
1 3/8"
4 31/32"
1550

locating tabs.*For 1310 & 1330 Special, only 2 caps are 1 1/8" & other 2 caps are 1 1/16" (primarily used on Ford applications).

 

[letsroll]

Thanks posidude. What I had in my original drive shaft hooking to the 8 inch was a 1310 special. I will need to switch to a 1310 standard to hook to the 9 inch. It just befuddles me that the N case with the daytona pinion has the smallest of u-joints. I was thinking about a different yoke to jump it up but the front u-joint is a 1310 so if it holds there it ought to hold at the back. Going to buy the strongest made though.

 

[Mercougar67]

I went through the same thing. It's very counter-intuitive. I went through the pile of drive shafts and found an original C6 390 application. It slid/fit right in.....

 

[dfwcatsclub]

I will need to switch to a 1310 standard to hook to the 9 inch. It just befuddles me that the N case with the daytona pinion has the smallest of u-joints.

You have an aftermarket yoke. It should have the 1330 yoke in it. The Spicer yokes are 1310, 1330, and 1350. Ford are 1310 special and 1330 special. Lots of choices out there. Need a factory yoke? The Daytona factory yoke should be 1330 special. I have one left in stock if you need one but it's not cheap and requires resetting the pinion nut.