Leaf spring drop

[dfosh]

I have a 68 GMC swb with leaf spring .Truck is stock and I was going to drop the rear then do the front. I got a flip kit from djm part # 1012 with their shock for this kit part #2100 this shock was 21 1/4 in extended and 12in compressed. The flip droped the back 5 and 1/2 inches their shock was longer then the original and bottomed out when the truck was put on the ground. I then did some searching on the site and tried a front shock on the rear kyb344068 this shock extended was 15 1/4 in compressed 9 3/4 in. These numbers should have given me about 3 in travel still bottomed the shock out .Djm said they had sold thousands of this kit and never had this problem. Any ideas ? Thanks in advance.