Brian is right all you need to do with the 6 lug trucks is to change to the earlier 5 lug rotors, and in the rear I believe I read somewhere that a "B" body 8 3/4 is almost a drop in, in the dakota.
the one going under my 46 panal truck is going to stay 6 lug as I allreay have some nice wheels for it but the next one will get changed over to the 5 lug and 8 3/4 rearend Ron...