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1969 455 engine block bolt sizes?

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Old Sep 21, 2012 | 06:44 AM
  #1  
atkinsom's Avatar
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Question 1969 455 engine block bolt sizes?

I just bought an engine stand from Princess auto and it came with metric bolts to mount to the engine block. They are hex M14x65 Grade 8.8 bolts and seem way too big even though I haven't pulled off the bell housing from the back of the engine block. What size SAE bolt should I get to be able to mount the 455 block onto the 1000lb rated engine stand once I pull the bell housing off? Thanks
Old Sep 21, 2012 | 07:00 AM
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TripDeuces's Avatar
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Bell housing bolts are 3/8x16. The length will depend on how long your bolt mounting pads are plus the amount in the block. That can be adjusted with washers to get it right
Old Sep 21, 2012 | 08:24 AM
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Thank You very much. I kind of calculated that I'll need about a 2.5 inch bolt based on the 65mm length that came with the stand.
Old Sep 21, 2012 | 09:06 AM
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There is nothing metric on a 455. M14 is huge, about 9/16 diameter. The biggest bolts on a 455 are the main cap bolts at 1/2 x 13 thread.
Old Sep 21, 2012 | 05:54 PM
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For those that buy the 1000lb engine stand from princess auto the bolt length needed is 3/8"x16X3.5" which gives you almost an extra inch to screw into the engine block. You can use a couple of washer to shim it to make it fit after screwing in the 1/2" into the block holes. See this thread I found after for info
https://classicoldsmobile.com/forums...ine-stand.html

Last edited by atkinsom; Sep 22, 2012 at 06:12 PM.
Old Sep 21, 2012 | 08:40 PM
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Originally Posted by Run to Rund
There is nothing metric on a 455. M14 is huge, about 9/16 diameter. The biggest bolts on a 455 are the main cap bolts at 1/2 x 13 thread.
Ballancer bolt
Old Sep 22, 2012 | 08:50 AM
  #7  
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I forgot--the balancer bolt is 3/4 fine thread, except on very early engines of the series (330,400, 425).
Old Jan 21, 2021 | 06:38 AM
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Nut and Stud Size help

What size is the stud and not that retains the heat riser shroud on the '69 455?
Old Jan 23, 2021 | 01:58 PM
  #9  
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Originally Posted by atkinsom
Thank You very much. I kind of calculated that I'll need about a 2.5 inch bolt based on the 65mm length that came with the stand.
I suppose you've figured this out by now...but...you should buy MUCH longer bolts, and then add some nuts or tubular spacers, so the flywheel end of the block has plenty of room for tool clearance.

I buy 5"--6" long bolts. Three half-inch nuts on each bolt between the block and the stupid-short standoffs on the engine-stand arms works out nice.
http://hbassociates.us/Cheap_Engine_Stand_02.jpg


The next thing you'll have to deal with is lengthening the slots for those arms, so you can lower the block in the stand. With the heads on, the engine is too top-heavy otherwise. The rectangular steel plate is just plain too small, but you can get a little more slot length.
http://hbassociates.us/Cheap_Engine_Stand_03.jpg


Leave it to the Communists, and the Communist Collaborators to cheapen the design something so simple. They save a few cents on material, and a few more cents on shipping it across the globe.

Last edited by Schurkey; Jan 23, 2021 at 02:02 PM.
Old Jan 24, 2021 | 10:25 AM
  #10  
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Originally Posted by Ron Gardner
What size is the stud and not that retains the heat riser shroud on the '69 455?
The threads on the stud are 7/16-20. The hex size for the nut is normally 11/16".
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