Is there a minimum amount of vacuum that the EEC needs to see on a 90 mustang? the reason for this question is, I am planing on swaping out the 302 & replacing it with a 557. I want to keep it fuel injected and use the factory A9L eec to control it. I have the TWEECER RT so i know I can change things like engine size, firing order and MAF & injector size. I am working with Lem Evans on cam selection for the big block. He asked what the min vacuum requirement was for the EFI system that I will be running. All I could tell him was that curently, I have a 302 with an f303 cam that pulls 14 to 15 lbs of vac at idle and all vac lines are plugged off except fuel pressure reg & brake booster. I told him that i have a MAF instead of a MAP sensor and the car is not equipped with a nock sensor but, I dont know if there is a min vac requirement. any help with this would be great. Thanks