I have heard some good stories and bad stories about alumina seal but I would
rather use the ceramic sealer (Moroso).  It is not like other sealers in that
they gunk up your system and the ceramic stuff gets flushed out after it sets
up.  Also all these other sealers plug up the hole but remain in thier "gunky"
form.  I think this is why they tend to last only short periods of time.  The
ceramic sealer air dries over night so that it becomes hard and really stops
the leak.  It takes a little more work to do the ceramic sealer than the other
ones (you can't just dump it in the antifreeze you have to drain the system
and put water in ((Pure? :) )) and then put in the sealer) but the end result
is alot more permanent.  Mine lasted for 3 months like that and I went on
trips to Boston and down to Georgia with it (I live in NJ) I finally sold the
engine and it was still holding great.
Some guys are probably tired of reading about my praise for this stuff by now
but it really helped me out when I was strapped and couldn't do the head
repair so I hope it helps some of you other Listees as well
Ken Wilford
John 3:16