83 Chevy SB crack repair...braze or JB Weld?

docben

Seaman
Joined
Jan 13, 2024
Messages
58
After cleaning my SB I noticed a hairline crack that needs repairing. After watching lots of YT videos of folks using JB Weld and others actually welding the cracks, it seems the JB Weld holds up and is far easier. Obviously, through prep work is essential. I am curious what this boating group prefers using either method. If using JB Weld, has it held up?

Also, two photos of the stampings tell me what? The first stamping may be hard to read...V05213WT is on top, and J777163 on bottom. The full casting number 14010207.
 

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Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
Messages
49,537
people weld up the 3.0 where the block cracks on the outside.

the V engines crack inside the lifter valley like you see where the block is the thinnest.

I would not attempt to fix an SBC block.

get an appropriate motor out of a truck at a u-pull it.
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,953
people weld up the 3.0 where the block cracks on the outside.

the V engines crack inside the lifter valley like you see where the block is the thinnest.

I would not attempt to fix an SBC block.

get an appropriate motor out of a truck at a u-pull it.
Ayuh,.... Swap in a different motor, that ain't cracked,.....

That block is junk,.....
 

ScottinAZ

Master Chief Petty Officer
Joined
Jun 25, 2009
Messages
831
reason folks "repair" the 3.0 is they are a bit harder to come by than a small block v-8. They also tend to leak to the OUTSIDE, whereas that small block WILL leak to the inside and ruin the rest of the engine with water contaminated oil..... its just a small block v-8... Chevy made MILLIONS of them since 1955..... get a new block, and not have to worry about it....
 

docben

Seaman
Joined
Jan 13, 2024
Messages
58
reason folks "repair" the 3.0 is they are a bit harder to come by than a small block v-8. They also tend to leak to the OUTSIDE, whereas that small block WILL leak to the inside and ruin the rest of the engine with water contaminated oil..... its just a small block v-8... Chevy made MILLIONS of them since 1955..... get a new block, and not have to worry about it....
Mine is not a 3.0.
After reading the comments, I decided to go out on a limb and repair all cracks with JB Weld. I watched dozens of successful stories on YT and figured I would chance it. In preparing the outside of the block for painting, I noticed another crack, so definitely the previous owners didn't winterize.
I looked up on EB for just blocks and surprised to find very few and they are pricey. Sure I could go to a junk yard but this takes time and effort and no guarantee the block I get is better. At least with this block, my cam, crank, pistons, etc., are in good shape.
No one answered my original question on the numbers. Also, a big 207 stamp is on each side and wonder what that meant back in the 80s?
On some other forums, the casting number was not so easily tracked down to determine it's history.
So I have 2 main cracks to monitor...one on the inside, one on the outside that I can track more easily.
 

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