There was one out for years that is now discontinued, brand name was Cagle I believe. I loved that one, I've heard Napa's is similar. I've got about a dozen Holley regulators running around so I haven't looked for one in quite some time. The Holleys work very well but you need a fuel pressure gauge mounted on the line to use them accurately. I got all these darn things included with their high volume electric fuel pumps. You wouldn't believe the fuel flow required to run two Dominators and a 2 or 3 stage nitrous system. Now that I'm more or less out of drag racing, it'll be awhile before I use these up. BTW an underhood fuel pressure gauge can be handy and they are pretty cheap ($20 /- USD)