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727 bolt size? Thread in trans #3067623
08/13/22 12:16 PM
08/13/22 12:16 PM
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Florida
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Hooking up my SB transmission and realized I’m missing 2 bolts.
All the other bolts thread into engine block.
These 2 are larger and thread into transmission?
Any idea what thread size is needed?
I’ve already got it bolted up, so hoping someone knows so I don’t have to go the trial and error route.

Thx

6DC5AFCB-B2E6-4EE9-AC15-DEA82BD29B7B.jpeg
Re: 727 bolt size? Thread in trans [Re: BDW] #3067628
08/13/22 12:23 PM
08/13/22 12:23 PM
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So Near, Yet So Far
topside Offline
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It's been a while, but I'm thinking 7/16 - 14 (coarse)...

Re: 727 bolt size? Thread in trans [Re: BDW] #3067647
08/13/22 01:26 PM
08/13/22 01:26 PM
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elmor353 Offline
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Are you sure those aren't for the guide pins on the back of the block?

Re: 727 bolt size? Thread in trans [Re: elmor353] #3067677
08/13/22 03:19 PM
08/13/22 03:19 PM
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moparx Offline
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the holes that are circled are for the guide pins.
the other [larger] threaded holes are 7/16-14 [course as has been mentioned] and the smaller holes are 1/4-20 thread.
the top threaded hole above the starter gets a stud that is 7/16-20 [fine] thread the starter hangs on. there is approximately 1 1/2" of stud hanging out of the bellhousing. [calibrated eyeball measurement biggrin]
i just double checked this on a 727 on the shelf.
beer

Re: 727 bolt size? Thread in trans [Re: moparx] #3067711
08/13/22 05:23 PM
08/13/22 05:23 PM
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Well, I may have circled the wrong holes.
What I'm sure of, is the 4 top holes are not threaded.
The 2 holes I need bolts for are threaded, they insert from engine side and thread into trans, and are larger than top 4 bolts.
Trans is mated to engine, I know this because I fought it for 2 hours getting those guide pins aligned.
Dust cover is installed, just these last 2 spots are missing bolts.

Found this pic, not mine, but this is starter side

1EBD938D-9E85-49F8-9268-D5E545C3554A.jpeg
Last edited by BDW; 08/13/22 05:34 PM.
Re: 727 bolt size? Thread in trans [Re: BDW] #3067856
08/14/22 01:19 PM
08/14/22 01:19 PM
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moparx Offline
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the top four unthreaded holes are for the 3/8-16 thread bolts that thread into the engine block. these, you know.
the two threaded holes you need bolts for are 7/16-14 thread. however, i am not sure of the length of these. "possibly" around 1 1/4" or 1 1/2" long. i'm just guessing on the length of these bolts.
i believe the starter bolt threads are 5/8-11 thread.
hope this helps out.
beer

Re: 727 bolt size? Thread in trans [Re: moparx] #3068089
08/15/22 08:34 AM
08/15/22 08:34 AM
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JohnRR Offline
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Originally Posted by moparx
the top four unthreaded holes are for the 3/8-16 thread bolts that thread into the engine block. these, you know.
the two threaded holes you need bolts for are 7/16-14 thread. however, i am not sure of the length of these. "possibly" around 1 1/4" or 1 1/2" long. I'm just guessing on the length of these bolts.
i believe the starter bolt threads are 5/8-11 thread.
hope this helps out.
beer


Starter bolts are also 7/16 , otherwise what you posted is correct.


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Re: 727 bolt size? Thread in trans [Re: JohnRR] #3068148
08/15/22 11:40 AM
08/15/22 11:40 AM
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moparx Offline
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John, i stand corrected !
i knew the starter bolts are 7/16 thread. i don't know why i stated they were 5/8". my mind was obviously wandering around in the "cobwebs" and got distracted !
i will gladly take any punishment deemed necessary for my bad behavior............. hammer spank ozbbq
beer

Re: 727 bolt size? Thread in trans [Re: moparx] #3068182
08/15/22 01:03 PM
08/15/22 01:03 PM
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JohnRR Offline
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Originally Posted by moparx
John, i stand corrected !
i knew the starter bolts are 7/16 thread. i don't know why i stated they were 5/8". my mind was obviously wandering around in the "cobwebs" and got distracted !
i will gladly take any punishment deemed necessary for my bad behavior............. hammer spank ozbbq
beer


5/8 to get it out ...


running up my post count some more .
Re: 727 bolt size? Thread in trans [Re: JohnRR] #3068214
08/15/22 03:06 PM
08/15/22 03:06 PM
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Yep, figured out the 2 bolts I need are the same as this starter bolts.
Looking like they need to be 7/16 course, ~2" long







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