Getting my 1971 Duster back on the road

Well, today marks the day that I decide to call it quits on the slant six. I would have loved to get it running, however when I pulled the intake and exhaust manifolds a stud snapped in the block and the extractor broke off in the stud (just my luck). While I could've solved that with some time and effort, when I got the top freeze plug removed to replace it I found a massive accumulation of rust and who knows what else inside the block. It really needs to be pulled and rebuilt, and if I'm pulling an engine I may as well put a 360 in that I have most of the parts for. So lets see where this adventure goes next!