4 inch lift install question

[conoco]

I just received my 4 inch lift. Springs all the way around and dual steering stabilizer and extended brake lines. Do I need the drop pitman arm for the install or will the stock arm work. Everything I have read some say yes, most say no. The kit didn't come with one. But other of the same kits for different year trucks do come with one. I guess I could fit it together and find out. I just don't want to have to wait a week to get the part if I need it. Any one have a 4 inch lift with the stock arm? Thank you.

Its for a 1972 GMC K2500