Depends on how versed you are in Volvo's. Some may remove a head in 2 hours or less, other's it could take all day and being in CT maybe some broken exhaust studs. On average I would say 6-10 hrs. Its not a bad job if there are no surprises.
98 is pretty easy. Just be prepared to buy a few sets of exhaust gaskets. They can be a pain. It's 2 hours to get the head off, maybe 5 to go back the other way if you've done it before. Head bolts are throw away.
Coolant light came on at about 90 on the highway, followed by the low oil light a few seconds later. Pulled off to the side and turned car off as quickly as possible, probably less than 30 seconds, and had it towed home. Engine had been run hard the last 15+ minutes.