[silverc4s]

Andrew,
Congratulations on a great set up, and thanks for sharing the pictures and description of your issues with us here.
I would like to contribute a bit of information to your effort that may save your car from total destruction someday.
I used that same diaphragm regulator (mine was Purolator branded) on my 2.4 targa with webers some years ago. It worked well, and allowed me to get my fuel pressure set just where I wanted it.
One fine Texas morning, I went for a spirited run through the empty hill country back roads, having a great time and enjoying the wonderful car. As I got back onto more traveled roads, I noticed that I was running pretty low on fuel. Funny, I thought I had almost a full tank 40 minutes ago, that's odd. Some people driving by were honking & waving as they passed, admiring my pretty little silver car, thinks I.
By the time I reached a service station, my fuel gauge was almost on empty, and I am thinking that something is amiss.
When I stopped & exited the car, I could smell gas very strongly, and when I looked at the back of the car (engine still running) there was a pool of fuel forming on the ground under the engine!

I was sitting at the pumps, engine running - so I very calmly shut the car off and opened the rear deck. On the drivers side, the engine tin was awash in fuel, and you could see wet gas all over the intake valve cover, etc. I slowly pushed the car away from the pumps, fortunately there was a hose bib and a water hose at the side of the 7-11 store, and I was able to coast over there, close enough to reach with the hose.
Only after I was able to thoroughly hose down my entire engine compartment, and the underside of the car, did I realize how very close to complete disaster I had been, and maybe still was.

It was easy to spot the leaking regulator. As soon as I turned the ignition on, fuel poured from a small hole in the bottom of the silver disc housing the diaphragm. I was able to remove the regulator, and had sufficient length on one hose to bypass that connection fro the drive home.

It was a very nervous drive, but I made it. Later, upon dis assembly, I could see that the diaphragm had split at the center where it is riveted to a metal disc. I would never use one of these regulators again, even on a lawn mower, let alone under the deck of a 911.

You may never see this problem, but I would ask you to please buy a proper fuel pump, or get a Holley type regulator, or some other more safe & reliable solution.