I'd say no. The previous owner had it done just a year ago, and obviously it didn't hold. I think both the engine block and head have been heat cycled too many times to trust. Plus I did the headgasket in my old NA, and it is a PITA. DOHC engine with a "valve cover" that has to be installed against valve spring pressure. And I think the rings are a bit worn as well at least on a couple cylinders.
I'd get a jy motor from a newer car. I hear many tales of wrecked Volvos in the junkyard with a sticker underhood saying the timing belt had just been serviced, as well.
Either choice, I don't have a shop to work in and I don't want to park it indefinitely. The Comanche is my future project.