I'm going to use both 12ga. pins for power, and drill/tap the plastic for a bolt/stud for my ground. There is a thick area (circular) on the plastic flange that is about .5" thick that I tapped for a m6x1.0 bolt. I will probably run a 10ga. ground.

sos wire kit uses 12 gauge from the battery to relay, them 14 gauge from relay to pump hanger 5 pin connector. With walbro450 you use the wiring already on the pump

Bringing this thread from the dead.
I have a problem, working with Jeff Evans to tune my 06 with SOS supercharger, id1050x and upgraded AEM 340 fuel pump with SOS rewiring kit. There is some sort of fuel pressure issue as on my previous tune to get 11.0 afr the injector duty had to be raised to 96% at redline to provide enough fuel, this is with 3.8" pulley and 9.5 psi (only). Does anyone have any idea what is the issue of the pump not being able to supply enough pressure? I used new fuel filter at the end of the tank and followed this thread in details. Jeff suspects o-ring being a culprit at the pump outlet - any thoughts? Thank you.

Check out this lengthy thread. Several potential things identified, buried in this post or that.

https://www.s2ki.com/forums/s2000-fo...boost-1208364/

any way you can check actual fuel pressure at the rail?

It's only one data point so take this for what it's worth to you. I've had that fuel pump do that exact thing on the dyno, and it only had the miles it took to drive to the dyno. My tuner immediately said the fuel pump itself was the culprit. We swamped pumps and all was good.

No option to attach a gauge, the pump is literally new with 200 miles on it. The only factor telling us that the pump might be a culprit is that to get desired AFR at redline we need to max 1050x, which comparably in other setups were in 70% Duty (vs 96% that we need to run). At this point my biggest question is it a pump or is there an o-ring or something else that would form an obstruction and bleed the fuel into the tank instead of sending towards the injectors? Let me know your thoughts.

Thank you.

Yes, such a restriction is mentioned in that thread I posted. Someone had such an issue, explains where it was, how they fixed it.

We had a Fuel pressure guage on the rail and could see the pressure drop during pulls. We also had to increase the duty cycle higher than it should of been to keep the AFRs reasonable, but had to stop to switch pumps. Them AEM pump was brand new. There's nothing external to the pump that can cause that change in pressure. There is a thread addressing these pumps. TLDR: get a walbro.