I have a 14 B FF and will be putting a D60 in my '87 K5. I will be running a 6" springs in the front and the Echobit ford shackle and ford 57" springs. I will be putting on eather 37x12.5 MT/Rs or 38x15.5 TSL radials on my truck. I was wounding if anyone could tell me how to figure out how far to move my front axle forward and my rear axle back and what degree shim I would need. Is there a sit I can goto to caculate this in? Thanks for your help.