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Discussion Starter #1
I recently swapped out my weak 8.8 axle in favor of a 9" out of a 79 F150. now my only problem is that it seams my driveshaft is too short. Im only catching about 1" in the slip yoke. im running factory rear springs with 2" taperd lift blooks of the 79. my truck is an 86 with a np435. i know where there is a 89 with an automatic and a 9" in it would that driveshaft work? i already stole the slip yoke part that attatches to the axle the rest is still on the bronco.
 

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Sway's jealous of my
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When going to a 9" you usually lose about 2" worth of driveline. You'll need to get your driveshaft reworked. If you're planning on lifting or anything, you should figure out your specs for that and either have a new shaft made or just wait till you can have the current one done for that lift. Or use your other shaft you have available and have it reworked properly.
 

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Discussion Starter #3
so you are telling me the driveshaft out of a late 80's bronco that came from the factory with a 9" has the same driveshaft as an 86 wiht an 8.8???
 

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Southeast Utah Native
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I going to assume that you meant to say EARLY 80's Bronco that came with a 9", because there weren't any 9" rears after about '83 or '84. Other than the length, yes the driveshaft is very likely the same. When I did the swap to a 9" my driveshaft from the 8.8 bolted right up, it is a couple of inches too short & I'm now experiencing noticeable wear in the slipjoint because of that. You can have a DS lengthened easily.

BTW, if you made the change to a 9" for strength, you wasted your time and money.
 

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Discussion Starter #5
i made the change because my spider gears where laying up and down highway 45 in houston texas.

and the 9" was a lot cheaper (Free) then the 8.8

the 9" has a lot more beef to it then an 8.8 i went from 28 spline axles to 31 spline. 2 spider gears to 4. the ring gears is a lot beffeier then the 8.8 along with the pinion gear.

there is more room for expansion on the 9" then ther is on the 8.8.

and sence everyone is saying lengthen the driveshaft, then where is a good place to get that done in Texas?????
 

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what trans do u have, a c6 driveshaft should be about 4" longer than an e40d, maybe just look for a DS out of a different vehicle w/ a different trans/t-case/axle setup, if u find one close maybe a lil long, good excuse for a lift!!;)
 
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