Having a issue with fuel pressure loss starts at 6 and slowly goes down as engine gets warmer to 3psi and when revving the engine she dips below 3psi. Any clues what that might be? It's a cheapo 6psi electric pump. Do these need to be rewired like the fc pumps do?
On a nikki or Holley, I wouldnt use one due to those having primary and secondary ports split apart by design. The spacer would make it so you didnt have the primary and secondary split. Weber, mikuni etc. It could add mid range torque by increasing runner length, but I don't think on a 12a you would notice it. Just my thoughts. I have unsuccessfully used one with a Holley. Never tried anything else