9 inch swap - The 1947 - Present Chevrolet & GMC Truck Message Board Network

71/454 · 11-22-2009, 03:53 PM

I am toying with the idea of doing a 9 inch in my truck since I keep breaking stuff. Anyone have any advice on this? I found a 79 f150 with almost the perfect width 65 1/4, but the ford pinion offset bothers me. I read a couple of threads where guys have one side narrowed to centre the pinion, and some others say just leave it. I have a one piece shaft and not alot of room around it in the crossmember so I'm not sure if I have the room to run it on an angle, and I don't really want to go thru the hassle of narrowing a diff. Anyone done this swap?

**clay68c10** · 11-22-2009, 11:43 PM

I've got a 70's Lincoln 9" in my 68 and the offset isn't that much, maybe 4" or so. I've got a 2 piece drivshaft so clearance wasn't an issue for me.
You could take your driveshaft loose and lay it over to the side and see how much room you've got. I bet you could make the crossmember hole bigger if needed and it wouldn't hurt anything.
If you haven't bought the truck axle yet, go find a 70's Lincoln, they're the right width and have a 5x5 bolt pattern and disc brakes. I bet the LTD's and Mercury whatevers are the same rear with drums.

tecky11 · 11-23-2009, 01:11 AM

the dana axels are pretty tough to break try them

71/454 · 11-23-2009, 02:51 AM

clay68c10 thanks I was thinking the same thing. I had a look at it tonight and I will try moving the shaft over to see what its like. I want to stay with the truck diff because they are 31 splines versus 28 for the cars and my wheels are 5 on 5 and 5 on 5.5 so the truck will work.
tecky11 the dana 60 is tough but it is tough to find around here, the 9 inch is still pretty common in junkyards locally

tecky11 · 11-23-2009, 02:58 AM

oops didnt see that your from canada!

**John Fabris** · 11-23-2009, 03:26 PM

I am also running a 9 in my 67. came out of a 75 lincoln, so it has 5 on 5, rear disc brakes, and 3:00 gearing. no power off the line, but fast and quiet on freeway....

71/454 · 11-25-2009, 12:07 AM

John fabris did you just leave the offset pinion alone and just let the driveshaft run to the side?

ripdog28 · 11-25-2009, 12:47 AM

I ordered mine so i did not have to worry but i would cut the ends off, center the housing, have someone weld up new ends or the old ones in a jig. Make sure they can weld and have a jig to do it. Then order new axles. I do not think you will have a prob.

**clay68c10** · 11-25-2009, 01:03 AM

Yeah, that 28 spline thing... Kinda sucks but it's not too tough to upgrade. New spider gears and axles is all.

**John Fabris** · 11-25-2009, 02:35 AM

I did not change anything and let the new one-piece driveshaft sit offset. Close clearance, but I have not had any problems with it. My truck is lowered 6" in back so I really don't have much travel to really swing the driveshaft...

71/454 · 11-26-2009, 04:10 PM

Thanks John, thats exactly the answer I was looking for!

11-22-2009, 03:53 PM	#1
71/454 Turbo Guy Join Date: Jan 2005 Location: Calgary Alberta Posts: 353	9 inch swap I am toying with the idea of doing a 9 inch in my truck since I keep breaking stuff. Anyone have any advice on this? I found a 79 f150 with almost the perfect width 65 1/4, but the ford pinion offset bothers me. I read a couple of threads where guys have one side narrowed to centre the pinion, and some others say just leave it. I have a one piece shaft and not alot of room around it in the crossmember so I'm not sure if I have the room to run it on an angle, and I don't really want to go thru the hassle of narrowing a diff. Anyone done this swap? __________________ 1972 Gmc Custom swb intercooled twin turbo 327 10.5-1 and 12 lbs of boost, Nodular iron case super t-10 4 speed with a blowproof bellhousing, 12 bolt eaton posi soon to have moser axles. 1998 Honda CR250 fully ported, case matched, milled head, vortexed carb and revalved suspension but don't forget the woody woodpecker decal kit! Things I've broken so far: 12 bolt diff saginaw 4 spd many, many pieces Aluminum case Super t-10 4 spd

11-22-2009, 11:43 PM	#2
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,990	Re: 9 inch swap I've got a 70's Lincoln 9" in my 68 and the offset isn't that much, maybe 4" or so. I've got a 2 piece drivshaft so clearance wasn't an issue for me. You could take your driveshaft loose and lay it over to the side and see how much room you've got. I bet you could make the crossmember hole bigger if needed and it wouldn't hurt anything. If you haven't bought the truck axle yet, go find a 70's Lincoln, they're the right width and have a 5x5 bolt pattern and disc brakes. I bet the LTD's and Mercury whatevers are the same rear with drums. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ Last edited by clay68c10; 11-22-2009 at 11:46 PM.

11-23-2009, 01:11 AM	#3
tecky11 Registered User Join Date: Jan 2009 Location: phoenix,AZ Posts: 451	Re: 9 inch swap the dana axels are pretty tough to break try them Last edited by tecky11; 11-23-2009 at 01:11 AM.

11-23-2009, 02:51 AM	#4
71/454 Turbo Guy Join Date: Jan 2005 Location: Calgary Alberta Posts: 353	Re: 9 inch swap clay68c10 thanks I was thinking the same thing. I had a look at it tonight and I will try moving the shaft over to see what its like. I want to stay with the truck diff because they are 31 splines versus 28 for the cars and my wheels are 5 on 5 and 5 on 5.5 so the truck will work. tecky11 the dana 60 is tough but it is tough to find around here, the 9 inch is still pretty common in junkyards locally __________________ 1972 Gmc Custom swb intercooled twin turbo 327 10.5-1 and 12 lbs of boost, Nodular iron case super t-10 4 speed with a blowproof bellhousing, 12 bolt eaton posi soon to have moser axles. 1998 Honda CR250 fully ported, case matched, milled head, vortexed carb and revalved suspension but don't forget the woody woodpecker decal kit! Things I've broken so far: 12 bolt diff saginaw 4 spd many, many pieces Aluminum case Super t-10 4 spd

11-23-2009, 02:58 AM	#5
tecky11 Registered User Join Date: Jan 2009 Location: phoenix,AZ Posts: 451	Re: 9 inch swap oops didnt see that your from canada!

11-23-2009, 03:26 PM	#6
John Fabris TOTY 2006 Join Date: Dec 1999 Location: Magalia CA USA Posts: 2,270	Re: 9 inch swap I am also running a 9 in my 67. came out of a 75 lincoln, so it has 5 on 5, rear disc brakes, and 3:00 gearing. no power off the line, but fast and quiet on freeway.... __________________ John Fabris 67 C10 SWB

11-25-2009, 12:07 AM	#7
71/454 Turbo Guy Join Date: Jan 2005 Location: Calgary Alberta Posts: 353	Re: 9 inch swap John fabris did you just leave the offset pinion alone and just let the driveshaft run to the side? __________________ 1972 Gmc Custom swb intercooled twin turbo 327 10.5-1 and 12 lbs of boost, Nodular iron case super t-10 4 speed with a blowproof bellhousing, 12 bolt eaton posi soon to have moser axles. 1998 Honda CR250 fully ported, case matched, milled head, vortexed carb and revalved suspension but don't forget the woody woodpecker decal kit! Things I've broken so far: 12 bolt diff saginaw 4 spd many, many pieces Aluminum case Super t-10 4 spd

11-25-2009, 12:47 AM	#8
ripdog28 Registered User Join Date: Apr 2008 Location: Imperial Beach, CA Posts: 1,040	Re: 9 inch swap I ordered mine so i did not have to worry but i would cut the ends off, center the housing, have someone weld up new ends or the old ones in a jig. Make sure they can weld and have a jig to do it. Then order new axles. I do not think you will have a prob. __________________ 69 c-10 BBC 462ci, forged crank, H-beam rods, 10.5-1 KB forged pistons, Dart Iron Eagle 308cc, Straub Cam, Comp Cams chrome moly full rollers, Weiand Team G, Prosystems 950, TH400/3500 Dalenzie stall, Currie 9+ Detroit Locker w/31spline axles.3.5/6in drop. My Build.

11-25-2009, 01:03 AM	#9
clay68c10 Senior Member Join Date: Aug 2004 Location: Centennial, CO Posts: 2,990	Re: 9 inch swap Yeah, that 28 spline thing... Kinda sucks but it's not too tough to upgrade. New spider gears and axles is all. __________________ ClusterTruck: 68 C10 Bought in 89, wrecked in 03. Slow low $ rebuild started '17. 6.0 & TKO http://67-72chevytrucks.com/vboard/s...d.php?t=788602 93 K1500 Short Step, 350, NV4500, EBL flash ECU. Vortec heads & roller cam someday... 05 Jeep Wrangler Unlimited. 3” lift & 6-speed 02 E320 the insurance total “free car” 13 Tahoe LTZ

11-25-2009, 02:35 AM	#10
John Fabris TOTY 2006 Join Date: Dec 1999 Location: Magalia CA USA Posts: 2,270	Re: 9 inch swap I did not change anything and let the new one-piece driveshaft sit offset. Close clearance, but I have not had any problems with it. My truck is lowered 6" in back so I really don't have much travel to really swing the driveshaft... __________________ John Fabris 67 C10 SWB

11-26-2009, 04:10 PM	#11
71/454 Turbo Guy Join Date: Jan 2005 Location: Calgary Alberta Posts: 353	Re: 9 inch swap Thanks John, thats exactly the answer I was looking for! __________________ 1972 Gmc Custom swb intercooled twin turbo 327 10.5-1 and 12 lbs of boost, Nodular iron case super t-10 4 speed with a blowproof bellhousing, 12 bolt eaton posi soon to have moser axles. 1998 Honda CR250 fully ported, case matched, milled head, vortexed carb and revalved suspension but don't forget the woody woodpecker decal kit! Things I've broken so far: 12 bolt diff saginaw 4 spd many, many pieces Aluminum case Super t-10 4 spd

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