Opti issue? 93 with 96 motor

I’ve rebuilt this LT1 and I don’t have the vacuum lines hooked up on the opti spark,(93 didn’t have a vented opti so I have to figure out how to run the lines)

What do yall think is causing the popping? Fuel pressure is fine, knock sensor is unplugged at the moment I’ve heard that retards the timing a bit

Any help is appreciated