My dad and I were 2 for 2 with having the Holley Volumax fuel regulator fail and allowing full psi/volume go to the carb. Mine happened going down the track.... literally had fuel pulling from the back of the hood. Flooded the engine bad and luckily I shut it down. I was very lucky that day. My dads occurred in the tech line at a track. Turned the pump on prior to starting and could hear the pump run, but no psi. Luckily he smelled and saw it before trying to start. It’s the Holley 12-704 style. Holley replaced both of them for free. The original design the simply pressed a brass piece into the aluminum housing where the spring and ball are retained. It eventually just hammered out the disc allowing full flow (we both ran Holley 250gph pumps). I took apart one of the new ones and they basically did the same thing as we did to continue to race with his car that weekend..... drilled a couple holes and retained the brass disc in with screws. Worth taking a peek if you have one of these large port regulators.