I had one just like that from over torque on the head bolt. It leaked coolant for a couple years till replaced the block. If you decide to try it, install a stud in the head bolt hole. Mine leaked no matter how I tried to seal it, I didn't try a stud. As the block warmed up, the cracked opened wider. It never ran coolant out, just always smelled of hot coolant and always had a drip on the bottom of the water pump. File it flat once the head is torqued down before installing the water pump, and set the block on end and drip Loc-tite into the crack or some other liquid that might run in to the crack and stay semi flexible. If you use a stud, be sure it threads to the bottom with thread locker, then use spacers to replace the head and torque the stud to pull it up into the threads while the thread locker dries.
If you try and weld it, the whole deck will need machined and possibly the bores since it will need preheated to weld. A stud threaded to the bottom may keep from pulling the corner clear off. I read somewhere that bolt gets 75 ft lbs where the others get 90, its been a while since I had a head off so the don't hold me to the 90 ft lbs. I took my block to a high tech weld shop and a machine shop, both said it was cheaper to replace then try and fix. I replaced it.
Last edited by Joe H; 03/20/2026 2:21 PM.
