Send the head off to Jerry (motorgeek) or carl (iceracer).  Both guys are fairly active on the site.  You likely pulled the threads due to over-tightening but it's ok if you have the larger studs installed.  The o-ring mod and stud mod are both a must if you own an 87 top end.  I know it's sucks when your bike is down, but everyone here has been there.  Just know after a few mods and little cash, you'll have a beast of a ride.   And reliable too.   The last few trips i've taken to the dunes, aside from a few bolts that fell off, the guys with the 4pokes are breaking down while the zilla cranks 1-3 kicks every time.