Like the title says.
One of the four mount to block bolts tightens to a certain point then releases can't imagine over tightened it with a quarter-inch ratchet.
Not looking forward to pulling the engine.
Any tricks out there?

 

Can you possibly use a longer bolt and catch undamaged threads? If not, time for a helicoil.

 

Thanks Joe

The strange part is it goes in a good half inch and seems like it's tightening then it releases. almost as if it was cracked.
I added a washer with no luck, is it possible it's bottoming out and I should add a few washers.

 

The threads near the top of the hole are stripped. Washers just give you even less thread engagement, so that's not what you want to do. Use a wire or drill bit to find out how deep the hole is, then see how far the bolt sticks out past the backside of the mount. Are you SURE you have the correct bolt thread? It almost sounds like you have the next size smaller bolt.

 

Besides the previous suggestions, if the threads can be chased or re-tapped & there's some good threads left, possibly use a stud & nut setup made from threaded rod. Last resort would be heli-coil or next size up tap/bolt.

 

Ok mystery solved, once again Joe was correct.
After pulling the header and mount it was easily apparent the 3/8 16 bolt was not the correct one how the others got as tight as they did is a wonder to me. (Guess AMK 4651 v8 bolt kit is for chebby)
So off to find the correct 7/16 14 1 inch.
I have seen various opinions on washer no washer, inline shows them with lock washers.
Time to check the assembly manual AGAIN.

Thanks, Joe.

 

The parts book confirms 7/16"-14 x 1" long bolts and a washer.

 

To the OP, note JoeP is stating a different thread per inch than you did. 20 TPI not 14.

 

Sorry, typo on my part, The parts book clearly shows 7/16-14. I don't know why I wrote it as fine thread. Doh! I edited the original thread.

 

I hope so cuz I just put 7/16 -14 bolts in there, wasn't sure so I just went with grade 8

 

I haven't spent enough time deciphering this thread for completeness; but, I was following along on your other thread and trying to determine deltas, if any; and, then, when you stated:

Did you order the incorrect bolts by mistake? The reason I ask is because isn't the frame the motor mounts are sitting on a Chevrolet frame (judging from your other thread)?

 

I made the mistake of thinking v8 GM (chevelle) motor mount bolts to block were, all the same, AMK does not list olds specific bolt kits. Yes, it's a frame from a Chevelle but in this case, the motor mount to block bolts it's irrelevant.
From my understanding, the only difference is the motor mount frame pads are bolted to a different set of holes on the frame for chevy.

 

This is always a safe bet. When in doubt: grade 8.