Your going to need a trans as well. The Nailhead bellhousing pattern is different then chevy. So, you will need a trans with a chevy belhousing. The radiator outlets are reversed meaning you will need a custom or post Nailhead radiator. you are going to need a midsump pan and pick up. I don't know what chevy offers there. You will need to fabricate your exhaust to the chevy manifolds. You will be able to use common BBC motor mounts , but you may have to fabricate the frame pads where they attach. Wiring harness may need to be lengthened and mover from side to side depending on starter placement. That is all I can think of for now.