Author Topic: 65 Buick Skylark Gran Sport Rear Posi Differential Info  (Read 996 times)

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Offline Coupeman

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65 Buick Skylark Gran Sport Rear Posi Differential Info
« on: January 19, 2017, 08:54:28 AM »
Can anybody help me out. I have 65 Skylark Gran Sport and was interested in putting a Posi rear differential in it. I have the unit but not sure if I want to use it.the Car has a single traction unit now and has a 3.23 gear in it the unit I have needs to use a spacer plate to use that gear is this normal on the BOP 10 Bolt 8,2 Rear ends? Any info on this would really be helpful. Thanks

Tony
Tony - Coupeman 34

1965 Skylark GS 400 Auto Hardtop
1968 Chevelle SS 396 Hardtop
1934 Ford 3 Window Coupe Streetrod
1974 Firebird Formula 350
1979 Camaro Z28

Offline WkillGS

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #1 on: January 19, 2017, 11:42:12 AM »
Sounds like you have a carrier for a 2.56-2.79. There was another carrier for  2.93 to 3.23, and a third for 3.36-up.
You might be able to use a ring gear spacer but it may have to be machined to the proper thickness. The wrong thickness will move the carrier too far to the right or left and the axle may not engage properly.

Best to contact Jim at JD Race. He has lots of experience with Buick rears:
http://www.jdrace.com/default.htm

Another option is to buy the correct carrier for your 3.23 gears. Auburn makes on, $414 from Summit Racing.
Walt K
Eastern Pa

66 GS Astro Blue/blue 425 auto
66 GS Silver Mist/black 401 4 spd
66 GS Flame Red/black 401 5 spd
66 GS Saddle Mist/black 401 L76 auto
66 Special Flame Red/black 300 5 spd
65 GS vert Verde Green/ Saddle buckets 401 4 spd
79 Turbo Regal

Offline Coupeman

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #2 on: January 19, 2017, 12:51:40 PM »
Thanks Walt, I appreciate the info and will reach out to Jim.

Tony
Tony - Coupeman 34

1965 Skylark GS 400 Auto Hardtop
1968 Chevelle SS 396 Hardtop
1934 Ford 3 Window Coupe Streetrod
1974 Firebird Formula 350
1979 Camaro Z28

Offline Brian

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #3 on: January 19, 2017, 01:49:00 PM »
Last I checked, Auburn only makes the posi carrier for the 3.36 and lower gears. 
'64 Skylark 2dr ht 4 speed, 300-4
'65 GS ht, 4 speed,2-4s,AC,PS,PB,PW,Pseat,Tilt
'66 Skylark 2dr ht 300-2 automatic
'78 Yamaha DT 400 2 stroke
'88 Ford F-150 4x4 (used to be 4x2)
'89 Ford F-350 4x4
'03 Honda Accord Coupe V6 6-speed manual (daily driver)

Offline WkillGS

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #4 on: January 19, 2017, 10:22:17 PM »
Last I checked, Auburn only makes the posi carrier for the 3.36 and lower gears.

I checked this morning before I posted. :icon_biggrin:
Auburn Gear #5420114 fits 2.93 to 3.23 gears,
#5420113 fits 3.36-up gears. ('up' meaning up to about a 4.30 gear)

Eaton has the carrier that only fits 3.36-up, and not the 2.93 to 3.23 gears.

There is some confusion out there whether these work on the later 68-70 8.2 rears. I believe they do work on the earlier 64-67 8.2. Best to check with Jim. He can set you up with used, rebuilt, or new parts.

Tony, let us know how you make out. I'm sure others here would like the info. :thumbsup:

« Last Edit: January 19, 2017, 10:27:05 PM by WkillGS »
Walt K
Eastern Pa

66 GS Astro Blue/blue 425 auto
66 GS Silver Mist/black 401 4 spd
66 GS Flame Red/black 401 5 spd
66 GS Saddle Mist/black 401 L76 auto
66 Special Flame Red/black 300 5 spd
65 GS vert Verde Green/ Saddle buckets 401 4 spd
79 Turbo Regal

Offline Brian

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #5 on: January 20, 2017, 08:32:05 AM »
Good to know that Auburn has one now for the 2.93-3.23 gear ratios!  When they first came out with the 8.2 BOP posi, all they offered was the 3.36 and lower.  I have been into a 68-up Buick 8.2 before and the posi made for a 64-67 8.2 won't work in it.  Ring gear has 7/16" bolts instead of 3/8" bolts and the carrier has a larger bearing on the drivers side than it does on the passenger side.  I tried to make one of the 68-up posi carriers worn in a 64-67 rear and it was a no-go. 
'64 Skylark 2dr ht 4 speed, 300-4
'65 GS ht, 4 speed,2-4s,AC,PS,PB,PW,Pseat,Tilt
'66 Skylark 2dr ht 300-2 automatic
'78 Yamaha DT 400 2 stroke
'88 Ford F-150 4x4 (used to be 4x2)
'89 Ford F-350 4x4
'03 Honda Accord Coupe V6 6-speed manual (daily driver)

Offline Coupeman

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Re: 65 Buick Skylark Gran Sport Rear Posi Differential Info
« Reply #6 on: January 23, 2017, 09:32:06 AM »
Thanks Walt and Brian for the updates. I really appreciate it and I will update everyone on this topic as I work on it.

Tony
Tony - Coupeman 34

1965 Skylark GS 400 Auto Hardtop
1968 Chevelle SS 396 Hardtop
1934 Ford 3 Window Coupe Streetrod
1974 Firebird Formula 350
1979 Camaro Z28