1987 Nissan Hub issues

Yep I have this beast and to be honest I really like it, the engine runs like a top everything still works great! (300k miles!!) The only gripe I have is the auto locking hubs. Has anyone changed over to manual locking hubs? I contacted the dealership and for the price of 380$ per side I can "change them" I have done some research on the net and found warn hubs for 220$ but I am afraid that there is some "conversion" part that is not included. So any help would be appreciated. And if it is not asking too much links to where I can purchase the parts needed