The SAS alone will take at least 1 week, there is a lot of custom fabrication you will have to do, but the 350 swap shouldn't be that bad, i belive novak sells an adaptor to install chev 350 Th350 and even bolt it up to the Nissan transfer case But if you do that, get a SLE (slip yoke eliminator)from calmini
are you going to go coil or leaf in the front?