swapping 8 1/4 for 8 3/4

putting an 8 3/4 in my 70 satellite. Any chance that I'd be lucky enough to be able to use the same driveshaft(lengthwise)???

Archives show it needing .66" to be cut but I would for sure mock it up & measure exactly. springs loaded, push the yoke all the way into the trans, measure C to C & subtract 3/4"-1"(w aftermarket flat output shaft seal)

I kept the same driveshaft and it's been fine for almost 15 years.

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Same swap in an F body. Driveshaft never cut. You may need to change the yoke on the dif or use a U-joint that has the two sizes on it. I found one at the local parts house. To do it correctly, the joint end needs to be changed, if you do that, have them knock the half inch off for peace of mind. You never know when you may hit something in the road and send the yoke slamming into the transmission tearing things up.

The difference in length from the axcle center line to the center line on the u-joint is about 3/4" with the 8.75 being longer. If you have 1.5" or more of extra depth available on the slip yoke you can do it with out cutting but if you have less than 1.5" you run the risk of the yoke bottoming in the tranny.

BTW, how did you wind up with an 8.25 in a 70 Satellite? The 8.25 is a stout rear end, not as stout as an 8.75, but certainly enough to live behind a mild big block or a hot small block.

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The difference in length from the axcle center line to the center line on the u-joint is about 3/4" with the 8.75 being longer. If you have 1.5" or more of extra depth available on the slip yoke you can do it with out cutting but if you have less than 1.5" you run the risk of the yoke bottoming in the tranny.

BTW, how did you wind up with an 8.25 in a 70 Satellite? The 8.25 is a stout rear end, not as stout as an 8.75, but certainly enough to live behind a mild big block or a hot small block.

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8 1/4 came out in '69 or 70 and was the base rear in the B's IIRC. it shows up in the '70 FSM I have for B bodies.