Hi. New here. BOUght a 1964 1/2 conv. Think it’s has a replaced 289 as it’s blue not gold. Not sure what year the tranny is. Need a NNS. Which one would I buy?? Also no wiring harness coming through the firewall to hook up to. Where do I find the reverse light to connect to and the circuit for it to only start in park and neutral?!?!