1973 Duster with make over

I haven't even thought about a motor yet. I'm gonna get the rear suspension buttoned up and the body panels welded back in. then tackle the body work. Im going to keep the slant 6 in it running to keep if mobile. I will most likely put a small blocked in it with the normal speed parts. I have been kicking around the idea of a v6 pentastar, but the tranny options are killing that idea unless someone comes up with adapter.