1980 SCC southern California classic 1 of 100

Q#1..has anyone here have one of these or know anyone who ever owned one.   basic mechanics of the car are the same as any 1980 coupe.  This model was (at the time) supposed to be Subaru's coming out of the dark ages party car.  They took 100, decaled them up after painting them black, gold pin stripes, 6 spoke alloy alum, trunk rack, fog lamps, etc                   Q#2..once and for all, explain the difference between GL and DL models.   paperwork says one thing but over the years mechanics say another.   Q#3.   My engine has finally run its course and my be dead.  My 19 year old over heated the car and my have cracked the already over extended head gasket.   Is there a retired or old school mechanic that can help me out.  Im in Long beach California