Which yoke/uni combo? 8 3/4 conversion on 318 - 7 1/4 Barracuda.

[OzCuda]

Need some help guys so that I get the right parts.  Putting an 8 3/4 diff into the Barracuda to replace the 7 1/4.  Have 29 spline 3.55 ring and pinion already and was going to order the yoke to suit but not sure what size uni joint was used on my 318 driveshaft?  Were there differences?  There seems to be multiple yokes available and ultimately I need to order the one that suits my original driveshaft.

Also wondering if the original driveshaft that came off the 904 auto trans will work with the 727 trans I am fitting??  If the drivesahft doesn't isn't compatible then the rear yoke becomes a side issue??

[tactransman]

Rearend Yoke ID Info  2 1/8" = 7260   2 5/8" = 7290
Driveshaft will need a 727 yoke installed on the front u-joint and shortened around 3 3/4 to 4 inches.

[Alaskan_TA]

There is also a conversion U-joint available that can mate a large yoke to a small one. From memory I believe the NAPA part number is 347 ?

Barry

[tactransman]

7260-7290 conversion U joint. Big to Small U Joint

TRW part # 20226.



Mancini ........... 5-527X
Auto Zone ........... 2-0527
NAPA ............... NUJ240-0369
Neapco ............. 2-0527

[OzCuda]

Thanks guys but I am a bit confused by the conversion U-joint option.  Working on the assumption that I have the small yoke on my driveshaft (measure that tonight), then my first option is get get the matching pinion yoke and get the matching uni joint.  As I understand it, I can order the larger pinion yoke and use the listed uni joint to adapt it to my driveshaft.  I'm guessing the only reason to go down this path is if they send me the wrong yoke so at least I have options, or if I am planning on upgrading the driveshaft later?

Will the smaller uni joint be sufficient for a mildly worked 383 driveline???


Also, if I have to modify the driveshaft anyway to shorten and fit 727  slip yoke, I suppose I should go the bigger joint anyway??

[tactransman]

I'm guessing the only reason to go down this path is if they send me the wrong yoke so at least I have options, or if I am planning on upgrading the driveshaft later? YES

Will the smaller uni joint be sufficient for a mildly worked 383 driveline??? YES


Also, if I have to modify the driveshaft anyway to shorten and fit 727  slip yoke, I suppose I should go the bigger joint anyway?? If you might go to more horsepower later

[Alaskan_TA]

Tact,
Did Napa change numbers? I have had this one in my tool box as a spare for years;

[tactransman]

  That info is from Moparts tech archives. http://www.moparts.com/Tech/Archive/shaft/4.html

[Alaskan_TA]

OK, I called my brother (he works for NAPA) the 347 number has been superceeded by the NUJ240-0369 number. 

Barry

[OzCuda]

Thanks guys, I measured up last night and I do have the smaller unis as expected.  One final question (I get my moneys worth out of you guys don't I), can you confirm that I am able to buy a 727 slip yoke that will take the 7260 uni?

Doh, I can use the adaptor uni if needed

[tactransman]

That is going to be the most common one to find in the salvage yards.