will the pinion yoke out of an 8.8 axle fit in a 9" axle? in other words is it just a straightforward swap?
b.t.w. the 8.8 is out of a 91 bronco and the 9" is out of an 81 f-150

 

I doubt it. The 8.8 and the 9 are two totally different units. I don't think anything is really swappable between the two.

 

NOPE.

sorry, but it is not even close. different spline count, diameter etc...

 

o.k. next question then. how can i get the bronco driveshaft to mate up to the f-150 9 inch? the 9 inch used u bolts to attach the shaft to the axle and the bronco uses a flange type driveshaft attachment

 

Are the u-joints the same size? If so, you can press the flange off and bolt them onto the 9" with it's u-bolts. I'm not familiar with the stock 9" I'm used to seeing them under race cars. My '87 has the 8.8" and has u-bolts, not the flange like you have, so they may be the same size, I don't know for sure.

 

anyone else have any suggestions?

 

I didn't crawl under and measure and all, But I was looking at my dad's 82 That had a whole 94 Frame and drive line swapped into it and my 86. My 96 has the 9" and his now has the 8.8. It looks like the 2 has the same joints. Since the Flange is held onto the shaft with u-joints you can probably remove that shaft Flange and Place it onto your drive shaft then just bolt it up like the 8.8. Just check your shaft travel after to be sure it has enough room to travel when flexed. If I don't come across the right 9" before to long I'll be doin a temp. 8.8 swap on my 79 Bronco it'll I find, save enough $$ to built a 9" or run across a 1 ton parts truck to rob the drive train from. Plus I'm kinda wondering how well the 8.8 fairs when 35" TSL boggers go to bitting.