10bolt vrs 12bolt

slayer74

Veteran Member
Jan 10, 2014
166
yonkers new york
recently picked up a 76 with a 383 stroker,guy claims it pushes out 450hp it currently has a 10 bolt 3:90 posi with that kind of hp should i upgrade to a 12 bolt? any thoughts sean
 

Gary S

Administrator
Lifetime Gold Member
Apr 14, 1999
24,524
Bismarck, North Dakota
Don't worry about the strength of the 10 bolt. In original trim, it is almost equal to an original trim 12 bolt in strength. If you need more, upgrade your 10 bolt with stronger parts rather than spend tons more for a 12 bolt.
The weakest spot on a 10 bolt is the axle tubes where they are welded into the center section.
 

big gear head

Veteran Member
Jul 30, 2001
6,443
Ky.
You can upgrade the 8.5 10 bolt to 30 spline axles. If you put sticky tires on it you need to read the thread about welding the axle tubes. This should be done by a professional.
 

Bumpad_Z28

Veteran Member
Apr 9, 2004
502
Logan, UT
10 bolts (8.5") version are plenty strong enough for almost every application !!! Including 450 HP 383's :)

"I" just found a deal on a 12 bolt so I pulled the trigger and won't have to worry about it again.

~DaVe
 

Coadster32

Veteran Member
Lifetime Gold Member
Oct 2, 2013
2,334
Milford,CT
If it helps...I have a383 stroker supposedly dyno'd at 525 @ flywheel, (who really knows). Anyhow I use a 10bolt 8.5 rear with 5:12's and posi. Beat the heck out of it w/o any problems.
 

Ihada70Z28B4

Veteran Member
Oct 4, 2002
210
Buffalo,NY,USA
The Grand Nationals came with the 8.5 and they are known to hold up just fine to alot more than that. I have seen plenty of 9-10 sec cars with upgraded axles and c clip eliminators.
 

Protour-Camaro

Veteran Member
Feb 16, 2012
2,111
California
This is like a BBC vs a SBC arguement. If you build the 10 bolt right, it will hold up. I wouldnt be so ingornat to say "I have a 12 bolt, I never have to worry again"....pssss...its not that great
 

Bumpad_Z28

Veteran Member
Apr 9, 2004
502
Logan, UT
Protour-Camaro said:
This is like a BBC vs a SBC arguement. If you build the 10 bolt right, it will hold up. I wouldnt be so ingornat to say "I have a 12 bolt, I never have to worry again"....pssss...its not that great

just more 12 bolt envy ... maybe it's not that great, but it's not iGNorant :confused: either ;)
 

Rich Schmidt

Veteran Member
Mar 27, 2010
4,285
Denville NJ
Dave Henninger and Kurt Urban ran their blue 70 Camaro into the 8's with their 8.5" 10 bolt and never had issues. As far as welding the axle tubes,the 12 bolt has the exact same tubes,and they need to be welded too,so there is no difference there. Theyuse all the same size bearings,and the 10 bolt uses 10 7/16" bolts to hold the ring gear on which is techincally more bolt then the 12 bolt's 12 3/8" bolts. Aside from the 28 spline axles,there is no real difference.
 




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