i HAVE A HIGH MILAGE ISUSZU TROOPER 1991,same eng as chevy . it has little compression if any on two cjclinders mentioned . i pulled the plugs blew air into #5 with toliet paper lit near number 3 , got nice flame from #3. got me thinking head gasket ? what do you think . this motor burns 1 qt. oil every 200 miles . its just a work ride so i don;t want to put too much money in it . if i pull the heads and its needs a new gassket . what work do you think i should have done to the heads. anyone have a good 2.8 for sale near state of az?