Try a Carter P4070. Its design goes back years, originally designed for a military application. I have been using them since I started with all this car nonsense, 47 years ago lol.
https://www.summitracing.com/parts/crt-p4070The summit ad says 4-8 pounds of pressure, yea I have never ever seen one go more then 6 with most in the 4-5 range which is perfect. No regulator needed. One thing, these Carter electric pumps use the fuel to cool the pump internally. So you need to install a filter before the pump. Otherwise, any junk in the tank or fuel that gets sucked in will jam the pump. For example
https://www.summitracing.com/parts/ado-gf952https://www.summitracing.com/parts/sum-230102Carter also sells a rubber isolator kit to keep vibrations down to a minimum.
https://www.summitracing.com/parts/CRT-18-14USafety wise you want to consider installing a carter fuel pump pressure switch. When installed and wired as designed, the pump gets voltage during cranking, then when the motor starts up, oil pressure keeps the circuit connected and the pump on. shut the motor off, or be involved in anything where the motor shuts off, as soon as the oil pressure drops, the switch does its thing, and the pump shuts off, automatically.
https://www.summitracing.com/parts/CRT-A68301Finally, you might consider using a fuel pump relay harness to eliminate any stress on the old wiring and to install another measure of safety.
https://www.summitracing.com/parts/mrg-40205gSeems like a little bit of work I know but in the end, these pumps are very reliable, long sorted out, and if installed and wired correctly, will give very good service, at least that has been my experience. In fact, I just did this very install for my son's 57 chevy with 261 motor, notwithstanding that I have run this exact set up in a couple of my vintage trucks and cars over the years.
