I have a 96 integra the block is a b18b1 with a gsr head i changed the cars wiring harness to ob1 how would I wire vtec which diagram should i use because i saw one that was called a dual buttery fly hook up? If anyone could help me out it would be helpful thank you

 

depends which head u using.. if u using gsr then aside from wiring vtec u will need to wire up aib valve or like u said "dual buttery fly hook up"

and if u using b16, r, or gsr with after market manifold then you only have to wire vtec, and knock sensor

also if u using obd1 harness, some plugs will not fit on ur b18b block like for alternator. wires are the same in both harnesses but u would need to swap up the plugs from ur obd2 harness. this will prevent u from changing the parts

GSR manifold:
Vtec solenoid (1 lead wire)
Vtec pressure sensor (2wires= 1 lead + 1 ground)
Knock sensor (1 lead wire)
IAB solenoid (2wires= 1 lead + 1 load)

Other:
Vtec solenoid (1 lead wire)
Vtec pressure sensor (2wires= 1 lead + 1 ground)
Knock sensor (1 lead wire)