I bought a 1976 Johnson 35 on an old boat at what I thought was a good
price. Several days deep into the restoration project, I find that I
have a seized bolt in the water pump impeller housing. The other three
came out fine, but that last one is extremely difficult to turn. I did
get it up a couple of threads and tried to get some Liquid Wrench to
run down, but I'm afraid it's (a) galled or (b) cross-threaded. What I
REALLY don't want to do is break it off in the lower unit casting. Any
suggestions for getting it out intact? Would heat from a propane torch
(a) expand the aluminum casting enough to remove the bolt or (b) damage
the lower unit casting?

Thanks in advance!