Whhoooaaaaa, Nelly! Bolt Head???? Bolt Head of WHAT? The MMO is good stuff, on occassions the motors rings or the pistons might try to stick to the bores in the block....
If Anyone is gonna have a motor thats gonna sit awhile, squirt some oil into the cylinders and turn it over some. I have several old shot glasses in my toolbox, I fill with liquid wrench or PBBlaster, I screw a special funnel in that has a piece of rubber hose on the end with a fitting that I have into the plug hole, pour the shotglass in, put plug in about 1/2 way, move to the next cylinder....I call it a fast pickle. A full pickle is where you completely fill the cylinders...be sure to label that motor that the cylinders are full....
Bolt head???? Where did this bolt head come from? You had the motor apart, Yes? If I have a motor apart and I stick the heads back on it:
1. I either take out the pushrods,
2. I tape off the intake face.
Usually do both....
I'm guessing here since there was not nearly enough info here to make a good response for you, if your saying a head bolt has a heat twisted off, that would not lock a motor up.
IF, IF your saying that you have to remove the head, pull all the rest of those bolts out, leave the one thats headless in, and gently pry and slide your head off so you can put either a stud puller w/long 1/2" breaker bar or Pipewrench, whichever yyou have.
IF your just wanting to pull out a broken head bolt, get a washer thats the same size as the stud, place it over the hole, now get a nut, lets say a 5/8's, or a old stripped wheel nut is what I normally use. I save shit like that for these things.....
Anyway, center the washer over the stud hole, center the nut over the washer, hold it in place with a pr of needlenose or visegrips, have your mig turned up, hold your tip in the center and let er rip. after you fill the nut at least 1/2 way, let it cool off for about 5 minutes, get a socket on your breaker bar, and unscrew it and replace with new one.
Always oil your threads or put antisieze on then....always....
Just for your info, A sbf or sbc are hard to beat. They are plentiful, they're everywhere, and everyone carrys parts for them