the y-pipe bolts are horrible and don't cheap out on the gasket set. If you buy a cheaper set, i gurantee the lower intake gasket will leak, buy the better set. In my opinion with that many miles i would rather just buy a used motor. I replaced my wifes 94 4.0L for $400. You'll have close to that in a good head job, between gaskets and machine shop, and with that many miles on that 4.0L you can pretty much count on a cracked head or two. And after you seal up the top end and make it fresh again how's the lower end gonna handle it?
I did head gasket on my 93, had a bad valve on drivers side back cyl. and the center cyl. on pass side had a chunk of valve missing. I never had an overheating problem but both heads ended up being cracked and the cracks were not even in the combustion chambers of the bad cyl's.
Just my $.02