Any extra long yoke options for the 9" differential?

[Gaugster]

Hunting for driveshaft solutions for my 6 Speed Auto swap into a FE equipped '68 Cougar. Any experts that know all about yokes? I have the 1330 (Big Cap) 4" yoke. It seems Ford had a 3" and a 4" version throughout the years. Looking for something like a 6" or 7" if available? I have high horsepower goals in the future so I will need to upgrade to a billet yoke and custom driveshaft someday. I received decent quotes for either a custom chromoly or aluminum unit but was also curious to see if something a little more economical was possible.

Newer V8 Mustang OEM driveshafts are a multi sectioned shaft and known to be a weak link. The 3.7L V6 Mustangs use a single shaft with an integrated slip yoke of sorts. Not legendary in strength either but they cost 100 bucks. So I took a chance and picked one up. It's steel and 3.5" diameter. Length is 56" but slips an inch or two. Per the picture it bolts up to the 6R80 automatic well but is a bit short.

Another route is to change the yoke to the more modern companion flange style. I have found one company (Currie) that makes a 35 spline billet flange yoke for the 9". I am checking with them about overall dimensions. It's expensive and overkill for now but may help towards future plans. This type of product is coming out of the Ford Truck world. Several spacers available for these flanges as part of lifted suspension kits. But these extra parts could easily put me halfway towards a custom shaft. Probably purchasing the custom shaft now but confirming it will work fine with a future upgraded yoke is the least hassle. I just think it would be cool to identify a low cost option for average powered applications.

[Falcon67]

First time I've heard anyone asking for a longer yoke LOL.  Every 9" swap into a Mustang or my Falcon has involved finding the short yokes because even the 4" was too long for use with the existing shaft and stock transmission location.  I've never see one longer than the 4".  Sounds like a driveshaft update, IMHO. 

[gt350hr]

 +1 do the driveshaft. A longer yoke  will lead to "mysterious" driveline harmonics . That's the reason none are longer.

[Gaugster]

Thanks guys. When doing my search I got the feeling I was going off the beaten path. Had to give it a shot though. 

[hbstang]

heres a 5 inch one on epay.i bought the 1350 one.he sells quality parts.
https://www.ebay.com/itm/9-Ford-1350-Long-Billet-Steel-Pinion-Yoke-5-Long-9-Inch-U-Bolts-NEW/372648161600?hash=item56c38fb140:g:mtQAAOxyzGlQ8NpR