Ford Mustang Forum banner

Status
Not open for further replies.
1 - 7 of 7 Posts
G

·
Discussion Starter #1
OK folks, I'm converting my car from 6 cyl to V8. It'll be a 289/C4 with an 8-inch, so essentially just a stock V8 car as far as this topic is concerned. I need to knowif my original driveshaft will work? Like if it's the same. I know on the C4 end it is the same, because the car had a C4 in it originally, but I'm wondering if things will be different because of the rear-ends. Any thoughts? Help, HELP!!
 

·
Registered
Joined
·
7 Posts
Ok, I just did a T-5 Swap on my 66 Mustang and I need to do some driveshaft modification, but on the Tranny end. As far as I can see from my Mustang, being that I have a 8 inch rear as well....the Universal Joint at the rear end side of the driveshaft is mounted to the rear end with a set of U bolts. So you shouldn't have any problem there but You will have problems at the Tranny end if you are replacing the Tranny as well. The aftermarket Yoke size and the U Joint (Spicer) don't exactly match if you aren't careful and it leaves about an inch of play room and slowly but surely the U joint will give up on you. So I say just go with a new driveshaft out of a V-8 Mustang...one with a C-4 and a 8 or 9 inch.

Check out this site....they have pretty good info
http://mustangandfords.com/howto/127_0412_veig/
 
G

·
Discussion Starter #3
A T5 swap is different than my situation. You're changing the tranny, I'm changing the rear-end.
 

·
Registered
Joined
·
114 Posts
Your rear U-joint won't match up at all, the 8 inch's yoke is set up for a larger U-joint. Perhaps there is a "conversion" joint that might help with this, I don't know. I do know your current driveshft will be about 3/4 inch too long. When I swapped an 8" into my 67 I was lucky enough to find a good driveshaft from an 8" C4 '70 coupe that fit perfectly. The '70 driveshaft was also a plain steel tube instead of the fairly weeny dual tube bonded by rubber one that came on my six cylinder coupe. Good luck with it!
 
G

·
Discussion Starter #6
Well I'm all kinds of confused. partsamerica.com lists the same part numbers for U-joints on an I6(7 1/4" rear-end) and a 289 car(8" rear).

Also, length is not a problem, if it's longer I can always have it shortened. I'm just worried if the U-joints are the same. You say they aren't, the other site says they are, I'm going crazy.
 

·
Registered
Joined
·
114 Posts
All I can tell is my old driveshaft would NOT go back in because of the length and rear U-joint issues after I put in my 8" rear. If it would have I sure would have used it since it would have saved me hunting another driveshaft. At the time I just wanted to be able to not have to push the car in and out of the garage. How strong or correct everything is/was wasn't an issue at that point I just wanted the car to be able to move itself.
Since you're talking about doing the exact same thing I did to the same kind of car I'm pretty well assuming you will run into the same issues. I could be wrong, wouldn't be the first time by a long shot. One sure way to find out...
 
1 - 7 of 7 Posts
Status
Not open for further replies.
Top