could someone possilbley with original factory rear speakers give me a measurement of exactly where they are located at so i can place the ones i bought in the salvage yard in the correct place. please specify how far from the rear, how far from the floor, etc. could someone also tell me what years of blazer come with the factory behind the seat roll bar (not rear one ) and when the roll bar become interegated in the frame. also if the factory roll bar will fit a a year of blazer with an interegated roll bar. thanks ahead of time and to all who have helped me in the past with their two cents. youve been great ! darrenolander galva,il. 1979chevycheyenneblazer 350/350 gettin'down on all fours, 4 a'little x4 play !