At least in Vermont the motor has to be the same year or newer in order to pass inspection, I am not sure if this is true in NY. I know people thats how I get mine inspected in VT, I plan on going LSX but if not LT1 when I get out of school. Carb swap was easy, there are companies that make harnesses for the LSX into an S-10, I would try going to S-10 specific site and start on research. s10forum.com is a good place to start.
I did a couple months of research and still had to overnight some parts from Jegs.