Fuel pump for 340 450hp ?
We’re running the M6270 pump on a 1978 360 with no clearance issues whatsoever. Clock it as needed, use the right fittings there’s no problems. Using a Street Demon 750 (which the manual states requires a slightly lower pressure than say a Holley) with no regulator. No issues with too much pressure at all. A regulator wouldn’t hurt though.