anybody with 85-87 with 700R4
 

Could you please measure your driveshaft length for me? it also has to be a long box. I need one that is right around 69" for my 72. I think one off these trucks should fit perfect since I have a 700R4 and longbox.

A drive shaft off a LWB truck should work. The frames are basically the same. I have a SWB truck and the drive shaft not adding the yoke for the tranny is 57 inches. Do you have a 12 bolt on your truck? If so the 85-87 1/2 ton trucks have 10 bolt rearends. You will need a bastard U joint to bolt up the drive shaft to the 12 bolt. I just replaced mine with NAPA part number 372 in the yellow box. I replaced my original 10 bolt with a 12 bolt. My truck also has the 700R4 combo.