If you drove it there I'd drive it from there to another shop. Or sign up for aaa should be around $100 and use them to have it towed if you don't feel comfortable driving it.
Just a quick search in my area but $6800-8000 for a rebuilt 6.2 with a 3 year/100k mile warranty. Car-part.com but before I'd go that route I would get a 2nd opinion. Or for a price like that I'd get a 3rd. Going from a tick to a cracked block is a big jump. If it were me and I brought it to another shop for a diagnosis I wouldn't tell them what the 1st shop said. A lot of places do not like doing diagnosis work if they can't just plug in their scanner and have it tell them exactly what's wrong.
Just a quick search in my area but $6800-8000 for a rebuilt 6.2 with a 3 year/100k mile warranty. Car-part.com but before I'd go that route I would get a 2nd opinion. Or for a price like that I'd get a 3rd. Going from a tick to a cracked block is a big jump. If it were me and I brought it to another shop for a diagnosis I wouldn't tell them what the 1st shop said. A lot of places do not like doing diagnosis work if they can't just plug in their scanner and have it tell them exactly what's wrong.