Hi guys, I am going from a 7 1/4 to a 8 3/4 in my 67 barracuda. Can I use my 7 1/4 U-bolts or do I need to get new ones? Also I have a 904 tranny, does anybody know how much shorter my driveshaft will need to be? Is there a standard measurement or do I need to wait till I get the rear end installed and then measure. It is a 67 barracuda with a 904 that was a 273 now a 340, Thanks.

Yes, you need new U bolts and yes, you need a different drive shaft -- there is a 2.26" length difference between your tranny and rear you are going to have to make up just swapping the rear.

You'll also need new bottom shock plates.

...and an e-brake cable

Okay, the housing I am buying is supposed to have the perches on it and in the correct position. Is that what you mean by shock plates. I also have a place that will shorten my driveshaft, that should work,right. Thanks...

Okay, so it sounds like I need to get some 8 3/4 shock plates. Thanks for all the info. I will take some more if anyone has anymore.

If I butt the driveshaft all the way to the tranny, and then add 3/4'' to 1'' won't it be too long?

If you you butt the driveshaft all the way forward, you need to substract 3/4-1" from the dimension.

Good luck, I did the change from 7 1/4 to 8 3/4 earlier this summer. Make sure you use the vented bolt to attach the rear brake hose to the axle housing.

[quote then butt the driveshaft all the way into the trans & measure how much needs to be taken off & add 3/4-1" to that figure.

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if 2" needs to be taken off then add 3/4-1" to that figure so ie 2&3/4-3" needs to come off. At least that's what I thought I was saying but you got it.

Thanks to all who replied. Excellent info..