Bellhousing bolt size?

bonestock87

Founding Member
Dec 19, 2001
732
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Cape Coral, FL
I need to mount this 4.6 shortblock to my engine stand and need to know what size the bolts are. I guess length isn't important (that's what she said) but thread size is. I got this motor w/o the tranny so I have no idea. I really don't want to pull a bolt out of my '03 just to find out. Thanks!!:nice:
 
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So I go into the Home Depot and ask the "bolt aisle" guy for an M10 approx. 3 to 3-1/4 inches long. He gives me 4 10mm-1 25x80mm bolts. The 80mm is right at 3-1/4 inches. I just got home with them and they will not thread into the back of the block. They are either too thick or the thread pitch is off. What's the deal?:shrug:
 
The diameter is spot on I believe. Matter of fact at first I thought that the threads in the block were probably just dirty. I threaded in about a half turn and the used the socket on it, very gently I might add, and I just could not make it thread through. When I pulled out the bolt after my last attempt, a tiny chunk was missing from the bolt. I checked the block to see if I had messed it up, but fortunately the bolt gave before the block. I got steel/zinc plated bolts.
 
Block bolt M10x1.5

Just pulled the tap that I have used multiple times to chase threads in a modular block. It is a M10 by 1.5.

I compared it to a M10x1.25 and the difference in thread pitch is not obvious as it would be with an SAE bolt. However, when the pitch is compared directly to each other, there is a difference.

Sorry about that. I knew off the top of my head the bolt was an M10. What I couldn't remember was the pitch. Hence the reason I left it off.
 
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