Hi,
Call this number and ask about the complete process including emissions and safety features that you will need. Don't for get to ask about a VIN. NYS will send you a package of information after you talk to these guys, follow the instructions to the letter and have all of your paperwork and invoices.
1(518)474-5282 / NYS Technical Services Bureau (DMV)
Link:
http://www.nydmv.state.ny.us/register.htm#homemade
Trust me, it's worth the inital pain to have a properly registered car in NYS.
--Mike / Turn Ten Racing, Inc.