Author Topic: 6.6L and 8.1L transmission bolt pattern?  (Read 4692 times)

Offline zieg85

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6.6L and 8.1L transmission bolt pattern?
« on: July 30, 2012, 06:17:22 PM »
Does it share the same standard bell housing bolt pattern as the SBC/BBC that we all know and love?  I am thinking a ZF6 speed out of a 2006 Silverado 2500HD specifically. 
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline pholliday1

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Re: 6.6L and 8.1L transmission bolt pattern?
« Reply #1 on: August 01, 2012, 03:16:51 PM »
zieg, can't tell you if its the same however in 03 i ordered a 8.1l with manual six speed that hauled axx ,when driven hard the clutch would slip (bad) eventually 6k miles the clutch went and at that time there were no upgrades for it because the tranny had an intregal bellhouseing and there was no way to increase the clutch size to match the hp. Not sure how many ponies you are running but it may be a concern. Other than that its a great tranny. hope it works out for you!
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Offline zieg85

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Re: 6.6L and 8.1L transmission bolt pattern?
« Reply #2 on: August 01, 2012, 04:16:05 PM »
Thanks for the reply.  As far as HP, just a stock untouched 454 with 131K on it.  I already have the juice clutch, just looking to upgrade from a SM465 down the road if it will work.  I have driven the 5 speed in the 01 with a 6.0L.
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Captkaos

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Re: 6.6L and 8.1L transmission bolt pattern?
« Reply #3 on: August 01, 2012, 08:39:12 PM »
They would be the same pretty much, the later ones after 1999 would not have the upper bolt hole, if they were different, so it would only be bolted with 5 instead of 6 bolts.  Not a big deal though.

Offline zieg85

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Re: 6.6L and 8.1L transmission bolt pattern?
« Reply #4 on: August 01, 2012, 10:05:25 PM »
They would be the same pretty much, the later ones after 1999 would not have the upper bolt hole, if they were different, so it would only be bolted with 5 instead of 6 bolts.  Not a big deal though.

Any insight on a pilot bushing and the rest of what is needed?  Anyone heard of a swap done?  I like the location of the shifter, looks about the same as a SM465.  It has a nice gear spread...with a nice OD
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
https://www.facebook.com/groups/248658382003506/

Offline Captkaos

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Re: 6.6L and 8.1L transmission bolt pattern?
« Reply #5 on: August 01, 2012, 10:24:46 PM »
They should just bolt up, but the Flywheel would be the big question.  Advanced Adapters would probably have the info you are looking for.  GM generally has used the same size pilot hole for years.