need help

[blkboot]

I lowered my 71 c-10 about a few weeks ago.i drop it 2 in da front and 5 in da back.i lower it without the bed on the truck,and sunday i put my old bed in it just to see how lower it was.it does nt look like it lower it much in the back and thtas what i wanted.my question is with a 5in drop in the back.do i need to chande the shock monts,to make it drop a little moreor what?i looked up under it and look at the bump stop over the rear end and i think i have about a two in gab between the bump stop and the rear end.please help me you guys.some pics will help to.