I have a 76 280z l28. A little about the issue, car does have a slightly larger cam .450 lift, 270 duration. Pallnet fuel rail, 210cc injectors, deleted most of the emissions items and made sure to cap off all vaccum lines. Timing is right athere 15 degrees, any lower and it will die out. I'm only getting 5in of vaccum at idle, and wot I'm getting about 10-12. Idle stays are 500rpm cold or hot. Running a little better when warmed up but not much. Fuel pressure is at 35psi and I have the stock rising rate regulator. Engine stumbles at first when the intake is opened. Could use some help if anyone has some ideas.