I have an opportunity to pick up a 93 TT. I went to take a look at it today and ending up doing a compression test. Cylinders 1-5 all read normal and are with 5-10 psi of each other. Cylinder #6 read 5 psi though. It's still running and idling but it's obviously rough. It's also smoking from the bay right by cylinder #6. Any ideas on what I'm looking at problem wise? I'm guessing either a cracked head gasket or shot piston ring. Any help is greatly appreciated.