threads pulled on flathead HEAD threads in block. new bigger metric bolt??? what size is the std bolt, 7/16"? right?

as above... head bolt threads in block pulled out. need new bolt? metric? ... 8 mm is close/bigger... big enuf? i have hard time believing helicoil works. too simple. seems like it wud pull that right out too with any amt of force... head bolt torque of... 140 INCH pounds, right?
 
You cannot drill and tap them all to 3/8" if that is your question.
The #7 head bolt is already too close to the cylinder and is a heat sensitive area that burns head gaskets with stock bolts.
Yes, you can heli-coil them, but you will want to stack the inserts and timing them can be a chore....

maybe get the LONGER bolt, cut out the cooling fin under that bolt that is LEAKING in corner by exhaust and put a NUT ON THE BOTTOM!!!!

head bolts come in 2 flavors, right? 2.25 and 2.5"? Y/n? the 2.25" is in there now, so swap it for one of the longer bolts after i cut off the cooling fin under it and finagle a nut in there ;) 5/16" bolts, not 7/16" YEs/no?
 
3/8" fine thread 24 TPI bolt? 2" long? the bolt that came out was 2.25" long... so that shd be close enuf to get enuf purchase to do a better job of sealing that the 5/16 course thread that pulled the alum threads in the block????
 

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You cannot drill and tap them all to 3/8" if that is your question.
The #7 head bolt is already too close to the cylinder and is a heat sensitive area that burns head gaskets with stock bolts.
Yes, you can heli-coil them, but you will want to stack the inserts and timing them can be a chore....

maybe get the LONGER bolt, cut out the cooling fin under that bolt that is LEAKING in corner by exhaust and put a NUT ON THE BOTTOM!!!!


head bolts come in 2 flavors, right? 2.25 and 2.5"? Y/n? the 2.25" is in there now, so swap it for one of the longer bolts after i cut off the cooling fin under it and finagle a nut in there ;) 5/16" bolts, not 7/16" YEs/no?
The head bolts come in two different lengths and are 5/16" coarse thread.
You can fix it however you choose, but my suggestion is to follow the advise that you quoted (that I gave earlier) or replace the block.


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Just drilled it with. 5/16" bit n 3/8" - 24 TPI TAP n bolt I had. Good enuf. Blew head gasket as it's still blowing smoke out of head. I thought the thread was pulled when I assembled it but hoped it was... Tight enuf not to leak. I was wrong.
 
gasket was blown anyway cuz the threads were pulled before i got it. new gasket on desk. almost tight... is NOT "good enuf" . lessons learned. never enuf time to do it right the first time... ALWAYS TIME to do it again.
 
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