Engine temperature rated epoxies: JB-Weld?

[Daniel Burk]

Has anyone tried JB-weld to epoxy in the bosses?

The stuff claims to be useful for a million uses including the repair 
of cracked engine blocks... I've seen several motorcycles with JB-welded
crank cases that leaked nary a drop of oil.  I've played with it for
a couple of projects, and even used it to bond thermocouples to
polycarbonate.  It seems to hold up to about 300 degrees F before it 
becomes really pliable.  Since the bosses are probably not under lots of 
tension (or should not be, anyway)  why not use it?  

Dan