Well then I'll share with you how I get the tough ones out.
I get a large nut with an ID just big enough to get my MIG welder rod in and weld the nut to whats left of the broken stud. Put enough washers under the nut to be welded on so when it turns it won't clash with the cylinder base lip. IF part of the the stud is broken below the case you will have to add metal to the end of the broken stud, to have something to weld the large nut to. It may take a few try's to get a good weld on the stud. You should be a fairly accomplished welder I might add. Once you have got a nut welded on. Have a helper heat the block gently,use a large breaker bar w/a socket that fits the OD of the nut you welded on and gently slowly back out the broken stud out of the block. 100% susses rate with this method.stud
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