Front lift springs

[84chevy]

got a set of used front lift springs for my k20 today, they look real nice almost new, only problem is i dont know if they are 4" or 6" lift, is there a way for me to find out before i install them? and will i need shims under them for my driveshaft angle? i know its bad to have blocks under the springs so i figure shims cant be good either? thank you

 

[Zembonez]

I don't know of any way to tell how much lift before installing them. Shims are fine for pinion angle correction - front or rear.

 

[84chevy]

I don't know of any way to tell how much lift before installing them. Shims are fine for pinion angle correction - front or rear.

thanks! well how do i tell after i install them? lol. im gonna need to lift the rear to the same hight, im not sure if its better to buy rear lift springs, use blocks or? i want it to handle and ride nice on roads, bumpy or not.