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swapping 8 1/4 for 8 3/4 #302072 04/28/09 02:54 PM 04/28/09 02:54 PM
Joined: Jan 2003 Posts: 1,945 roanoke va kbcuda OP top fuel
kbcuda OP top fuel Joined: Jan 2003 Posts: 1,945 roanoke va	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)??? 5193474-0307091009c.jpg (81 downloads)

Re: swapping 8 1/4 for 8 3/4 [Re: kbcuda] #302073 04/28/09 03:40 PM 04/28/09 03:40 PM
Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,040 Lincoln Nebraska	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) live every 24 hour block of time like it's your last day on earth

Re: swapping 8 1/4 for 8 3/4 [Re: kbcuda] #302074 04/29/09 05:40 AM 04/29/09 05:40 AM
Joined: Jan 2003 Posts: 2,015 Frederick, MD 7 71charger top fuel
71charger top fuel 7 Joined: Jan 2003 Posts: 2,015 Frederick, MD	I kept the same driveshaft and it's been fine for almost 15 years. Previous Thread

Re: swapping 8 1/4 for 8 3/4 [Re: 71charger] #302075 04/29/09 07:01 AM 04/29/09 07:01 AM
Joined: Nov 2006 Posts: 1,086 Baton Rouge, La. StandOnIt super stock
StandOnIt super stock Joined: Nov 2006 Posts: 1,086 Baton Rouge, La.	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. 76' Volare, 5.9 magnum w/Iron heads. New best 10.68 at 123 mph 1/4 mile.

Re: swapping 8 1/4 for 8 3/4 [Re: kbcuda] #302076 04/29/09 07:53 PM 04/29/09 07:53 PM
Joined: Apr 2004 Posts: 1,396 Mass dgc333 pro stock
dgc333 pro stock Joined: Apr 2004 Posts: 1,396 Mass	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. Dave Clement Pembroke, MA 03 PT Cruiser GT Turbo 99 Dakota SLT+ CC 4x4 68 Barracuda sport coupe http://home.comcast.net/~dgc333/

Re: swapping 8 1/4 for 8 3/4 [Re: dgc333] #302077 04/30/09 08:22 AM 04/30/09 08:22 AM
Joined: Jan 2003 Posts: 16,123 Grand Haven, MI patrick I Live Here
patrick I Live Here Joined: Jan 2003 Posts: 16,123 Grand Haven, MI	Quote: 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. 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. 1976 Spinnaker White Plymouth Duster, /6 A833OD 1986 Silver/Twilight Blue Chrysler 5th Ave HotRod SOLD!* 2011 Toxic Orange Dodge Charger R/T 2017 Grand Cherokee Overland 2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)

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