I Have begun my install of my new Tuff Country EZ ride 4" lift Springs on my 72 blazer. The Rear springs Part #19670 seems to be too short, it is pulling the rear shackle forward where the bolt is right at the front lip of the frame mount for the shackle. Is this going to be ok? i have read in the installation manual (i read the instructions actually, go figure) where there is a special note to SOME 69-72 vehicles may come special order with 56" rear leaf spring. That is Part#19671. Am I going to be ok or should i return these and get the longer springs. Also if you have done this, will the longer springs be too long for the K5 blazer under heavy compression? I may need new shackles for the longer ones maybe?