In preparation for the arrival tomorrow of MB Old School 17x8 wheels, I pulled the wheels of my 65 fastback tonight. All of the suspension is new and I was told by the previous owner that it had the Shelby mod control arms with 620 springs. Now the rear, I have no clue. Can anyone identify what the springs are by looking at them? The have the writing "4-1/2 M10" on them. The car has the typical "sag" look to it and I'd like to fix that once I get the new wheels on. Everything is less than 3 years old. Any ideas since I dunno what the leafs are? I suppose I could cut the front a bit, but it's already low and the 17's are gonna be a tight fit. Oh, it does have the Shelby traction bars as well. Thx!