Have you seen another one of these?

[84 400]

Before ebay post it on your local cregislist. it is free and there might just bee a 73 to 87 truck nut on there that nows what you have. For ebay it will be exposed to a larger audance and it will prob reach the right people like us who value these trucks. No one will pay 5 k for it if they are just a normal joe looking at it but on ebay you will reach the people who are looking for these to restore and to customize. Make sure you harp on the RARE ness and that it is even more rare because it is tbi. Should bring you 5-7k. goood luck i would say list it in the clasifides on here but then you will pay the 25 dollar fee and probobly not use this site after but i think ebay charges 45$ to post a truc so maybe posting here would be worth the money.