1970 chevelle LS6 and L78 rear springs

[P.J.]

does anyone know what the factory height of the 70 chevelle
LS6 and the L78 is from the ground to the wheel openning mouldings front and back? The assembly manual shows 2 different part numbers for the front and rear springs was the L34 a different height than the L78 and ls6? The reason I am wondering is that I used the origional springs in my resto and when finnished the car sits lower in the back by 2 inches than the front. I know that over the years the constant pounding of the big block on the rear end took its toll on the spring height. I want to get it right
Please help
suprss70
Thanks
suprss70