Fuel pressure regulator plumbing : 850 Demon with a Carter mech. pump

Last year during my quest to stop the detonation, I rigged a fuel pressure guage to a long rubber fuel line then taped the guage to the windshield so I could see the pressure at WOT. At idle it was 6-7 lbs and it never dropped below 5 at WOT.

I'm surprised that I was running 11 lbs and the car ran fine. I had 2 different guages on it with the same #s so I'm pretty sure the readings were accurate.

Today I pulled the Carter and put the Holley back on. The pressure was back between 6 & 7 lbs again and the car ran fine. I'll keep the Carter pump and maybe plumb a regulator and return line sometime later.
Thanks for the help guys, Greg