What pressure is best for a 2000 mpi 502 with stainless marine headers, vortec flame arrestor, and arizona speed ecu. Also does anyone suggest any guage set ups so I can check the pressure. I broke my ass installing the regulator, and want to find a easy way to check the pressure. I know where to check but don't know who makes a guage to test the pressure. Anyone have any suggestions or help.

was wondering what gains you got from this whole set up ?

Have not tested, should be in the water by next weekend. Will post the amount of speed I picked up once I do some testing.

I spoke to Jim @ Az Speed last week about fuel pressures on a blown '97-454 EFI's that they built. He said that 48-55# was adequate for my Procharged twins. The ECU supposedly senses the need for more fuel and opens the injectors longer to allow more fuel into the cylinder.......personally, I thought it should be higher, but they are the ones that did developement work with Mercury on the ECU. They should know.

My 99 Mag MPI had a different fitting than earlier ones. I found a pressure gage at Pep Boys with an adapter that worked. Check the fuel pressure by turning key to run without cranking and let the 2 second prime give you your static reading (gotta read it before the pump stops). Really should have checked what the factory reg was before the change (too late!) Start at factory official pressure (or ask Arizona S&M) and go up in two psi increments with a top speed run at each until you get your best, then try going down but don't lean out. I added a psi above the top speed setting to make sure I didn't go lean.

Thanks for the info guys, I just happen to stop by pep boys before I got back to my computer. They sell a guage set up for fuel injection and it only cost $45.00 so I bought it. My problem was I didn't want to spend over a $125.00 for a snap on guage set up, that I would only use once. Anyone in my area that needs to use it contact me and you can save money, I will gladely lone it to you! THANKS AGAIN! I will also post my results as soon as I have them.

Paul are you hauling ass on this board?