L28 Rough idle after head gasket. Need help.

[dexter72]

Have you tried swapping the fuel hoses at the metal fuel lines at the fuel rail?. Usually the engine won't run if they are swapped but maybe yours will and this is your problem.

[DuoWing]

When I turbo swapped my 76' I swapped for a solid-lifter head, new timing chain, oil pump, etc. Put it all back together and had a hell of a time getting my car to run right. The biggest issue was vacuum leaks everywhere, yet I couldn't seem to find them with brake parts/carb cleaner. What I did was remove the boot from the throttle body, and cap off the exhaust. Also tried to cap off anything else that could leak. Using a vacuum port and a portable air tank along with a vacuum/boost gauge I pressurized the manifold to only 3-4psi. I used the water and dawn in a spray bottle to spray all over the manifold and managed to find bubbles coming from every which way. I kept fixing until my motor was seemingly holding pressure or bleeding off very slowly. I do have a leak in the exhaust which was bleeding off and there may be one or two more in the intake that I didn't come across, but once I did this and fixed all my leaks it made a huge difference. Like you I was going through every piece of electrical, pulling injectors and flow testing them, swapping out mafs, sensors, fuel pump regulators, etc. Also I did have my FPR set a little high which helped straighten things out when I brought it down.