1998 GMC 7.4L L29 cylinder 1 and 3 Missfire ?

[Rbrackman92]

Hello everyone I'm in need of some help ? I have a 1998 GMC sierra one ton crew cab long box with the 7400 l29 and i have a misfire in cylinder 1 and cylinder 3 when i bring the RPM above 2500 misfire in cylinder 1 goes away but misfire in cylinder 3 is still there?
i have just replaced the
- fuel injectors six hole to 4 hole nozzle
- Cap and Rotor
- plugs and wires
- Map sensor
any help would be greatly appreciated ?

 

[Schurkey]

1 and 3 are right next to each other. What is the cranking compression pressure of those two, compared to cylinders that don't misfire?

What is the condition of the distributor shaft bushings, and the gear on the bottom of the distributor? Can you wiggle or turn the distributor shaft? Is your crank/cam sensor alignment still within spec of plus/minus 2 degrees at 1100 rpm?